Dat Biology

Front 1

What is the cuticle?

Back 1

The cuticle is a thin, waxy layer that covers the upper surface of leaves. Its purpose is to prevent water loss.

Front 2

What is the upper epidermis level (plant)

Back 2

A single layer of clear cells that allows light to pass through, also involved in preventing the loss of water

Front 3

What are the constituents of a vascular bundle and what is their purpose?

Back 3

Xylem - carry water and minerals from the roots through the stem and into leaves
Phloem - cells that carry sugar and starch from the leaf down through the stem and into roots for storage

Front 4

What is the spongy mesophyll level?

Back 4

The spongy mesophyll layer contains cells with chloroplasts and is a major site of photosynthesis

Front 5

What is the palisade layer?

Back 5

This layer contains long columnar cells that are packed tightly together. Palisade layer cells contain chloroplasts and are the main photosynthetic cells.

Front 6

What is the air space?

Back 6

Air spaces are found in the spongy mesophyll layer and function in the exchange of CO2 and O2

Front 7

Stomate

Back 7

An opening in the lower epidermis that allows CO2 into the leaf and H2O and O2 out.

Front 8

Transpiration

Back 8

The loss of water by a leaf

Front 9

Guard cells

Back 9

Cells containing chloroplasts that create an opening in the bottom of the leaf during the day that is closed at night.

Front 10

Which cell layers of a leaf are capable of photosynthesis?

Back 10

The spongy mesophyll layer and the palisade layer

Front 11

What differentiates the upper epidermis layer from the lower epidermis?

Back 11

The upper epidermis has a waxy cuticle layer, while the lower does not. The lower epidermis has stomates/guard cells, while the upper does not.

Front 12

What color of light is most readily absorbed by chlorophyll?

Back 12

Red

Front 13

What is chlorophyll

Back 13

A green pigment found inside the chloroplast that traps light energy and splits water into oxygen and hydrogen

Front 14

What are the light reactions?

Back 14

The light reactions are a series of processes that require light to split H2O to produce H2 and O2. H2 is then reacted with NADP to produce NADPH and H+, which are utilized in the dark reactions

Front 15

What are the dark reactions?

Back 15

AKA the Calvin cycle

The dark reactions are a cycle of reactions that produce glucose.

1. 3CO2's + 3RDP -> 3 unstable 6C molecules
2. 3 ustable 6C molecules break into 6 3C PGA molecules
3. 6 PGA molecules combine with NADPH to make 6 PGAL molecules
4. 1 PGAL is used to make glucose, while the other 5 PGAL's rearrage to form 3 RDPs that combine with CO2 to star the cycle once more

Front 16

What are PGAL molecules for?

Back 16

PGAL molecules are used to create RDP molecules (calvin cycle), glucose (and starch), proteins and lipids.

Front 17

Why is green light not utilized for photosynthesis?

Back 17

Green light is reflected by chlorophyll, rather than absorbed, which makes it unavailable to the plant as energy.

Front 18

During the light reactions, NADP is _____ed and is the _________ agent

Back 18

reduced; oxidizing

Front 19

What is the purpose of the stem in vascular plants?

Back 19

Stems support leaves and serve as the pathway for the transport of water/minerals from the roots and the transport of glucose to the roots.

Front 20

How do dicots and monocots differ as far as where the vascular bundles are located in the stem?

Back 20

In dicots, the vascular bundles are located directly behind the bark. In monocots, the vascular bundles are scattered throughout the stem

Front 21

What are lenticels?

Back 21

Lenticels are small openings in the stem that alow oxygen in and CO2 out.

Front 22

What is translocation?

Back 22

Translocation is the movement of food through a plant

Front 23

What is the cambium

Back 23

The cambium is a cell layer located in the vascular bundle. Cambium contains meristematic cells that are capable of producing xylem and phloem. These cells die in the winter and reproduce once more in the spring and make new xylem/phloem.

Front 24

Vascular bundles of monocots conain cambium cells (T/F)

Back 24

False; monocots do not have cambium cells, and thus usually only live for one growing season and then die when the cold kills the xylem/phloem.

Front 25

What does girdling do to a dicot?

Back 25

Dicots have vascular bundles right under the bark, and girdling is the act of removing the bark around the tree. This disrupts the continuity of the vascular structures and disables their ability to transport nutrients.

Front 26

What is the function of the root?

Back 26

The root absorbs water and minerals and sends these up through the stem to the leaves. The roots also store starch.

Front 27

What is the function of root hair cells?

Back 27

These are cells with an expansive surface area, whose function is to absorb water from the soil.

Front 28

What is at the center of a root?

Back 28

The vascular cylinder, which contains xylem and phloem. Cortex cells, which surround this structure, store food.

Front 29

Starch is digested by an enzyme called ____ to form ____ monomers

Back 29

amylase; glucose

Front 30

Proteins is digested by an enzyme called ____ to form ____ monomers

Back 30

protease; amino acid

Front 31

Lipids is digested by an enzyme called ____ to form ____ monomers

Back 31

lipase; fatty acids/glycerol

Front 32

The involuntary process by which food moves down the esophagus is called

Back 32

peristalisis

Front 33

Pepsinogen is activated by _______ to make _______, whose function is to _______.

Back 33

Hydrochloric acid; pepsin; digest protein into small polypeptides and amino acids.

Front 34

Bile is produced by the _____, stored in the _______ and whose purpose is to _______

Back 34

liver; gall bladder; emulsify fats

Front 35

Describe digestion in animal-like protists (amoeba and paramecium)

Back 35

Food is digested in food vacuoles, and digestion is intracellular.

Front 36

Describe circulation in animal-like protists (amoeba and paramecium)

Back 36

protists do not have circulatory system as they are unicellular, but nutrients circulate due to cytoplasmic movement.

Front 37

Describe respiration in animal-like protists (amoeba and paramecium)

Back 37

Animal-like protists obtain oxygen by passive diffusion from the surrounding environment (water)

Front 38

Describe excretion in animal-like protists (amoeba and paramecium)

Back 38

Protists produce CO2, NH3 and H2O as waste. CO2 and NH3 exit via passive diffusion. Paramecium has a contractile vacuole which stores water.

Front 39

Describe locomotionin animal-like protists (amoeba and paramecium)

Back 39

Amoeba movie via pseudopods or cellular extensions. Paramecium moves via cilia, or small hairs that beat back and forth.

Front 40

Describe regulation in animal-like protists (amoeba and paramecium)

Back 40

Protists do not have endocrine or nervous systems but are able to respont to food stimuli

Front 41

Describe reproduction in animal-like protists (amoeba and paramecium)

Back 41

Reproduce by mitosis. May share genetic info via conjugation

Front 42

How does substrate level phosphorylation differ from oxidative phosphorylation?

Back 42

Substrate level - the energy needed to phosphorylate ADP comes from the substrate

Oxidative - the energy needed to phosphorylate ADP comes from protons moving down the gradient (electron transport/ATPsnythase)

Front 43

Why is anaerobic respiration necessary?

Back 43

It is needed to regenerate NAD+ for glycolysis and krebs cycle

Front 44

What are the two types of anaerobic respiration?

Back 44

Alcohol fermentation (pyruvate -> CO2 + NAD(+) + ethanol) and lactic acid fermentation (pyruvate -> lactate + NAD+)

Front 45

What is the purpose of oxygen in aerobic respiration?

Back 45

Oxygen accepts electrons at the end of the ETC.

Front 46

The purpose of the light reactions is:

Back 46

To generate NADPH and ATP

Front 47

In plants, a proton gradient is created within the ________, which drives the production of ____ through a proess known as _______

Back 47

thylakoid lumen;
ATP;
oxidative phosphorylation

Front 48

What is photorespiration?

Back 48

Photorespiration is when O2 is fixed instead of CO2 by rubsico. This results in toxic byproducts (peroxides) and molecules with a lower energy than glucose

Front 49

What is rubisco?

Back 49

Rubisco is a protein that fixes CO2 to make a high energy 3-carbon molecule

Front 50

What are two methods plants are known to use to minimize photorespiration?

Back 50

CAM and C4 photosynthesis

Front 51

What is C4 photosynthesis? What are the advantages and disadvantages of C4 photosynthesis?

Back 51

CO2 is stored in the intermediate form of malate, which is transfered from the mesophyll cells to bundle sheath cells where it is converted back into CO2. This means minimal oxygen is present where the calvin cycle takes place.

C4 photosynthesis is when intermediates are used to make photosynthesis more efficient. BUT - converting pyruvate to PEP requires ATP.

Front 52

What is CAM photosynthesis?

Back 52

CO2 is converted into malic acid at night, which is stored in a vacuole. In the day, it is converted back into CO2 for photosynthesis.

Front 53

The calvin cycle takes place in the ______

Back 53

Stroma of a chloroplast

Front 54

The product of noncyclic photophosphorylation is _____, while the product of cyclic photophosphorylation is ______

Back 54

NADPH; ATP

Front 55

Prophase (Mitosis)

Back 55

1) nuclear envelope disappears
2) Chromatin condenses into chromosomes (consisting of two identical chromatids)
3) mitotic spindle forms - tubules connect to the kinetochore

Front 56

Metaphase (Mitosis)

Back 56

Chromosomes are lined up at the metaphase plate in the middle of the cell.

Front 57

Anaphase (Mitosis)

Back 57

Spindle fibers pull apart the chromatids, forming twice the number of chromosomes as in metaphase.

Front 58

Telophase (Mitosis)

Back 58

Nuclear envelope reappears; chromosomes disperse into chromatin, nucleoli reappears

Front 59

What is cytokinesis and how does it differ between plants and animals?

Back 59

The separation of cells after telophase. In animals, there is a cleave furrow formed by tightening microfilaments. In plants, a cell plate forms by vesicles made by the golgi body - this becomes the new membrane and the cell wall develops between.

Front 60

Duplication of DNA takes place in which phase of the cell cycle?

Back 60

S phase

Front 61

Genetic exchange takes place during which meiotic stage?

Back 61

Prophase I

Front 62

Spores are _____ (haploid/diploid) cells that divide by mitosis to form a multicellular haploid structure, called the _______

Back 62

haploid; gametophyte

Front 63

The gametophyte generation produces ______ which fuse to form the _____; if the this structure forms a multicellular organism, it is known as the _____, which is (haploid/diploid)

Back 63

gametes; zygote; sporophyte; diploid

Front 64

What three factors contribute to genetic variation in meiosis?

Back 64

Crossing over (the exchange of genetic info across tetrads)
Independent assortment (uknown which chromosomes will go where) random joining of gametes (unknown which gametes will join during fertilization)

Front 65

What functional limitations limit the size of the cell?

Back 65

Surface-to-Volume ratio: volume increases at a faster rate than surface area when a cell grows. Large cells become inefficient at exchange.

Genome-to-Volume ratio: the genome stays the same size while the volume increases; eventually the genome cannot produce enough materials for cell activity.

Front 66

What cell specific factors influnece when cells divide?

Back 66

1. G1 checkpoint - cell needs a signal to begin DNA synthesis
2. G2 checkpoint - cell needs signal to start prophase
3. M checkpoint - cell needs signal to start anaphase

Front 67

What is the function of Cdk enzymes?

Back 67

In the presence of cyclin, Cdk's phosphorylate proteins involved in cell cycle regulation.

Front 68

What two physical, extrinsic factors regulate cell division?

Back 68

Density-dependent inhibition (cells cannot divide if the surrounding cell density reaches a threshold) and Anchorage dependence (cells only divide if they are anchored to a surface; do not divide if suspended in solution)

Front 69

If a cell has 46 chromosomes at the beginning of mitosis, then how many chromosomes and chromatids are there at anaphase?

Back 69

92 chromosomes/chromatids

Front 70

If a cell has 46 chromosomes at the beginning of meiosis, then how many chromosomes and chromatids are there at anaphase I?

Back 70

46 chromosomes/92 chromatids

Front 71

All eukaryotic cells have centrioles: T/F

Back 71

False, plant cells do not have centrioles

Front 72

Cytokenisis begins during ______.
Chromosomes begin moving to opposite poles during _______.
MTOC's migrate to opposite poles during ______.
Chromosomes replicate during ________.

Back 72

Telophase;
Anaphase;
Prophase;
Interphase

Front 73

Crossing over occurs during which cell division stage?

Back 73

Prophase I of meiosis - chromosomes pair (synapsis) forming tetrads - chiasmata are the points of crossing over

Front 74

Incomplete Dominance

Back 74

Both alleles are partially expressed in heterozygous individuals forming an intermediate form.

Front 75

Codominance

Back 75

A pattern of expression where both alleles are completely expressed in homozygotes.

Front 76

Epistasis

Back 76

One gene affects the phenotypic expression of a second gene

Front 77

Pleiotropy

Back 77

Occurs when a single gene has more than one phenotypic expression

Front 78

Polygenic inheritance

Back 78

When a phenotype is influenced by a multitude of genes and causes continuous variation - opposite of pleiotropy -

Front 79

Linked genes

Back 79

Genes that do not obey law of independent assortment - reside on the same chromosome and are inherited together.

Front 80

X-inactivation

Back 80

In female mammals - one of the X chrom's is condensed (Barr body) this occurs randomly and causes some cells to express gene from the maternal X and others that express genes from the paternal X.

Front 81

Nondisjunction

Back 81

failure of chromosome pairs or chromatids of a single chromosome to properly separate during meiosis or mitosis

Front 82

Polyploidy

Back 82

All chromosomes undergo meiotic nondisjunction, producing gametes with twice the number of chromosomes. Common in plants

Front 83

mosaicism

Back 83

During mitosis occuring in very early devlopment, causes mosaicism (some cells exhibit nondisjunction, others don't)

Front 84

Describe different types of point mutations

Back 84

Substitution - the correct nucleotide is replaced by a different one
Deletion - base pair is omitted
Insertion - extra base pair is added

Front 85

Aneuploidy

Back 85

A genome with an extra or missing chromosome - often caused by nondisjunction - aneuploid organisms are often sterile

Front 86

Down Syndrome

Back 86

aka Trisomy 21 - caused by nondisjunction of the 21 chromosome, causing an extra chr.21 to be present (total 47 chromosomes)

Front 87

Turner syndrome

Back 87

Caused by nondisjunction of sex chromosomes - females w/ Turner's have only one X chromosome

Front 88

The inheritance of skin color in humans is an example of which of the following?

Back 88

Polygenic inheritance

Front 89

Helicase

Back 89

an enzyme that breaks the H-bonds in the DNA double helix forming a replication fork

Front 90

DNA Polymersase

Back 90

assembles the new DNA strand using the template strand in the 3' to 5' direction

Front 91

Okazaki fragments

Back 91

Short lengths of DNA assembled on the lagging (5' to 3') template strand

Front 92

DNA Ligase

Back 92

Protein that joins okazaki fragments together.

Front 93

Primase

Back 93

An enzyme that places down a short segment of RNA on the leading and lagging strands - since DNA Pol cannot bind to single helix

Front 94

What problem occurs at the telomeres with DNA replication?

Back 94

When the primer is removed from the end of a DNA chain, there is nowhere for the DNA Pol to attach (usually there is a preceding okazaki fragment)

Front 95

What is the function of telomerase

Back 95

Telomerase extends the length of a DNA strand with nonsense fragments - prevents the loss of important DNA.

Front 96

What are the three steps of protein synthesis?

Back 96

Transcription, mRNA processing, translation

Front 97

What is the function of mRNA

Back 97

A single strand of RNA that provides a template used for sequencing amino acids into a polypeptide

Front 98

How many possible codons are there?

Back 98

64 (codon contains 3 amino acids, and there are 4 types of amino acid: 4x4x4=64)

Front 99

What is the function of tRNA

Back 99

transfer RNA: short RNA molecule that uses the brings amino acids to the ribosome and attaches to the mRNA codons

Front 100

What is the function of rRNA?

Back 100

Ribosomal RNA - building blocks or ribosomes, the protein assembly plants.

Front 101

What are the three steps of transcription?

Back 101

Initiation, elongation, and termination

Front 102

Initiation (of transcription)

Back 102

RNA polymerase attaches to a promoter region on the DNA and unzips DNA - often contains a TATA sequences

Front 103

Elongation (of transcription)

Back 103

RNA polymerase creates a new RNA strand as it unzips the DNA strand. Proceeds in the 5' to 3' direction

Front 104

Termination (of transcription)

Back 104

Occurs when RNA Pol reaches a sequences that terminates transcription (often contains AAAAA chain)

Front 105

What 4 events take place during mRNA processing (between transcription and translation)

Back 105

addition of a 5' cap and a poly A tail; RNA splicing; and alternative splicing

Front 106

What is the function of a 5' cap and a poly-A tail

Back 106

5' cap - makes RNA more stable and is a point of attachment to the small ribosome subunit

Poly-A Tail - provides stability and helps mRNA move across the nuc. envelope

Front 107

RNA splicing

Back 107

snRNP's splice out (remove) introns, regions of the mRNA that are not expressed - leaving only exons which ARE expressed (EXons are EXpressed)

Front 108

Alternative splicing

Back 108

Allows different mRNA's to be generated from the same RNA transcript by the splicing of exons in different orders.

Front 109

The first step of translation is...

Back 109

Initiation

small ribosomal subunit attaches to the 5' end of the mRNA.

Following this, a tRNA containing a methionine AA attaches to the AUG codon (start codon)

finally, the large ribo-subunit attaches to the small one, with the tRNA occupying the P site

Front 110

The second step of translation is...

Back 110

Elongation
1. tRNA binds to the A site of the ribosome
2. the AA on the tRNA in the P site is attached to the AA on the tRNA in the A site.
3. The tRNA in the P site leaves via the E site, as the tRNA in the A site moves to the now-vacant P site.

Front 111

The third step of translation is...

Back 111

Termination - occurs when a ribosome encounters a stop codon (UGA, UAG, or UAA) - releases the polypeptide from the tRNA, the tRNA from the ribosome, and the ribo-subunits form each other.

Front 112

Frameshift mutation

Back 112

When a deletion or insertion causes all subsequent nucleotides to be displaced one position, thus causing the codons to change as wel

Front 113

silent mutation

Back 113

the mutated codon continues to code for the same amino acid

Front 114

missense mutation

Back 114

New codon codes for a new amino acid

Front 115

Nonsense mutation

Back 115

occurs when the new codon codes for a stop codon

Front 116

What mechanisms do cells have for repairing replication errors?

Back 116

Proofreading - DNA Pol checks to make sure that nucleotides of base pairs are correctly matched

Mismatch repair - enzymes repair errors that escaped the DNA Pol proofreading

Excision repair - enzymes remove nucleotides damaged by mutages

Front 117

What is the difference between euchromatin and heterochromatin

Back 117

Euchromatin - regions where DNA is loosely bound to nucleosomes

Heterochromatin - represents areas where the nucleosomes are more tightly consisting of inactive DNA

Front 118

Transposons

Back 118

transposable genetic elements that can move from one location on a genome to another - sometimes have the effect of changing expression of genes

Front 119

Viruses usually consist of what three structures?

Back 119

Nucleic acid: single/double-stranded RNA or DNA that is the hereditary informationof the virus
Capsid - encloses the genetic material and consists of capsomeres
Envelope - surrounds the capsid incorporates

Front 120

The main function of the large intestine is the:
a. absorption of water
b. digestion of carbohydrates
c. digestion of fats
d. absorption of water
e. production of bile

Back 120

D

The main function of the large intestine is to absorb water to form feces

Front 121

ATP is required for all of the following except:
a. active transport by transport proteins
b. facilitated diffusion
c. microtubule movement within flagella
d. Na+/K+ pump activity
e. protein synthesis

Back 121

B

Facilitated diffusion allows large or polar molecules to pass through the cell membrane, but they can go down the electrochemical gradient

Front 122

DNA replication occurs during:

A. Anaphase
B. Interphase
C. Metaphase
D. Prophase
E. Telophase

Back 122

B

DNA replication takes place during the S stage (between G1 and G2 phases) of interphase

Front 123

Which is LEAST soluble in water?
a. cysteine (an amino acid)
b. glucose
c. sucrose
d. NaCl
e. hexane

Back 123

E

Hexane is least soluble as it is non-polar. The rest of the answers are polar or ionic species.

Front 124

The lac operon:

a. is found in eukaryotic cells
b. codes for the sequence of amino acids in lactase
c. regulates the translation of mRNA
d. regulates transcription by turning on or off the production of a repressor protein
e. regulates DNA replication by turning on or off the production of an inducer protein.

Back 124

D

Front 125

Food storage occurs in the:

a. embryo
b. coleoptile
c. cotyledon
d. germ
e. plumule

Back 125

C

Food storage occurs in the cotyledon

Front 126

All of the following statements about endosperm in angiosperms are correct EXCEPT:
a. it has a triploid chromosome number
b. It forms a portion of the embryo sac that contains the polar nulceii
c. It provides nutrients for the growing embryo
d. It forms entirely from maternal tissue
e. It originates from a cell that is fertilized by a sperm nucleus from a pollen grain

Back 126

D

The endosperm is where nutrients are stored in seeds. It forms from the union of two polar nulceii in the embryo sac with one of the sperm nucleii. Thus, the endosperm is triploid and both maternal and paternal in origin.

Front 127

The primary function of progesterone in the menstrual cycle is to:
A. stimulate development of the egg
B. Stimulate development of the endometrium
C. Stimulate development of the corpus luteum
D. stimulate development of the follicle
E. Trigger ovulation

Back 127

B

The primary function of progesterone is to stimulate the development of the endometrium.z

Front 128

Both viruses and prokaryotes contain:
A. nucleic acids
B. ribosomes
C. a plasma membrane
D. a protein coat
E. a peptidoglycan wall

Back 128

A

Both viruses and prokaryotes contain nucleic acids (genetic material)

Viruses have protein coats, while bacteria have ribosomes, a plasma membrane and a peptidoglycan cell wall

Front 129

Which of the following is an anabolic reaction?
A. ATP + H2O -> ADP + Pi
B. Cellular respiration
C. starch + n(H2O) -> n(glucose)
D. CO2 + H2O -> glucose + O2
E. glycolysis

Back 129

D

Anabolic reactions are those that build more complex molecules from less complex molecules. D is an example of photosynthesis, while the other examples are all catabolic reactions

Front 130

Which of the following macromolecules will disulfide linkages be found along their standard structures?

A. Nucleotides
B. Carbohydrates
C. Lipids
D. Proteins
E. Cholesterols

Back 130

Correct Answer: D

A. Nucleotides – C, H, O, N, P
B. Carbohydrates – C, H, O
C. Lipids – C, H, O
D. Proteins – C, H, O, N, S
E. Cholesterols – C, H, O

Front 131

Highest content of oxygen in the fetal circulation system may be traced at the
A. umbilical artery.
B. umbilical vein.
C. pulmonary vein.
D. pulmonary artery.
E. aorta.

Back 131

Correct Answer: B

Because the fetal lungs are still underdeveloped and non-functional, gas exchanges are phenomenally carried out at the placenta. And as observed there, deoxygenated red blood cells (RBCs) in the umbilical artery are adequately rejuvenated prior to giving rise to highly oxygenated RBCs flowing next to the umbilical vein.

Front 132

All of the following statements pertain to kingdom Monera EXCEPT for one. What is that one EXCEPTION?

A. Common shapes of prokaryotes are spherical, rod, or helical.
B. DNA molecule is double stranded.
C. Genetic recombination can occur through transformation, conjugation, or transduction.
D. DNA molecule is concentrated in nucleoid region in the form of a ring.
E. Peptidoglycans are absent in gram negative bacteria.

Back 132

Correct Answer: E

Additional comments to all of the statements presented:

A. Known examples are like streptococcus (spherically in chain), pseudomonas (rod-shaped bacillus), and spirillum (helically shaped).

B & D. Relatively small amount of protein is associated; smaller and simpler ones are called plasmids.

C. Generally, transformation occurs via uptake of naked genes from surrounding environment, conjugation via one way passage of F plasmid, and transduction via the aid of viral carriers.

E. Peptidoglycans are polymers of modified sugars cross-linked by short polypeptides. Both gram positive and gram negative bacteria possess these components, with the cell walls of the latter having lesser amount of peptidoglycans but are more structurally complex.

Front 133

The static allele frequencies, leading possibly to threat of extinction among the cheetah population, is closely related to a condition called

A. punctuated equilibrium.
B. catastrophism.
C. genetic variation.
D. hybridization.
E. genetic equilibrium.

Back 133

Correct Answer: E

This question relates to the well-known Hardy-Weinberg theorem, asserting that population equilibrium (same allele and genotype frequencies in successive generations) remains constant in the absence of microevolution factors. Do not panic if you cannot find Hardy-Weinberg equilibrium as one of the answer choices. Question of this nature deliberately tests your ability to identify the closest alternative, which is none other than E alone.

Front 134

In a plant, blue petal (B) is dominant to white petal (b); and long stem (L) is dominant to short stem (l). Determine the parental genotypes if 299 blue petal long stem, 302 blue petal short stem, 103 white petal long stem, and 98 white petal short stem plants are produced.

A. BbLl x Bbll
B. BbLl x BbLl
C. BBll x BbLl
D. Bbll x bbLl
E. bbLl x bbLl

Back 134

Correct Answer: A

# of blue petals : # of white petal

(299 + 302) : (103 + 98)

601 : 201

~ 3 : 1 _ Parental genotype: Bb x Bb ---------- (1)

# of long stems : # of short stems

(299 + 103) : (302 + 98)

402 : 400

~ 1 : 1 _ Parental genotype: Ll x ll or ll x Ll ---------- (2)

Combining (1) & (2),

Possible parental genotypes: BbLl x Bbll or Bbll x BbLl

Front 135

Osteoclasts

A. are bone forming cells.
B. deposit Ca2+ in bones in the presence of calcitonins.
C. deposit Ca2+ in bones in the presence of parathyroid hormones.
D. release Ca2+ from bones in the presence of parathyroid hormones.
E. are similar in homeostatic functions to osteoblasts.

Back 135

Correct Answer: D

In bone remodeling, osteoblasts deposit Ca2+ in bones in the presence of calcitonins while osteoclasts release Ca2+ from bones in the presence of parathyroid hormones.

The above processes are intimately linked to the homeostatic control of blood calcium level.

Front 136

The magnesium-containing porphyrin ring of a chlorophyll is similar in structure to

A. the fluid mosaic model of a membrane.
B. the heme group of a hemoglobin.
C. the ribosome bound to an endoplasmic reticulum.
D. the protein covalently bonded to a carbohydrate.
E. the cristae of an inner mitochondrial membrane.

Back 136

Correct Answer: B

The molecular structure of concern is characteristically represented by a metal/transition element surrounded by a complex carbon ring, which in turn attaches itself to several other protein subunits. Besides chlorophylls and hemoglobins, cytochromes found along the electron transport chains also exhibit similar relationship discussed in this problem.

Front 137

Binding of a substrate to one subunit of an enzyme leads to active conformations of all other subunits. Which of the following mechanisms describes such enzymatic control?

A. Cooperativity
B. Feedback inhibition
C. Multienzyme complex formation
D. Allosteric inhibition
E. Organelles specificity

Back 137

Correct Answer: A

Cooperativity generally serves to amplify enzymatic responses to substrate bindings, as augmented by information given in the question. Rest of the incorrect mechanisms is explained as follows:

Feedback inhibition – regulation of metabolic pathways via the threshold amount of end products accumulated to inhibit front-end enzymes

Multienzyme complex formation – an assembly of enzymes facilitating metabolic processes along the pathway

Allosteric inhibition – inactive form of enzymes aggravated

Organelles specificity – membranes encapsulation of enzymes designated for specific metabolic functions

Front 138

A father with group A blood and a mother with group O blood had their first son born with group O blood. What will be the possible blood group genotype(s) on the next child conceived? I. IAIA
II. IAi
III. ii
A. II only
B. III only
C. I & II
D. I & III
E. II & III

Back 138

Correct Answer: E

The birth of a type O child reveals that the father’s blood group genotype may only be heterozygous, IAi.

Hence, crossing of the blood group genotypes from both parents again will produce either a type A (IAi) or a type O (ii) child.

Front 139

Which of the following enzymes is NOT present in the human small intestine?
A. Trypsin
B. Amylase
C. Pepsin
D. Nuclease
E. Lipase

Back 139

Correct Answer: C

Distinguished for their affinities to exceptionally low pH environment, pepsins are a primary group of enzymes designated to hydrolyze protein molecules to smaller polypeptides in the stomach .

Front 140

Choose the CORRECT properties of enzymes. I. Catalytic proteins shifting reactions away from their equilibrium positions
II. Lowering activation energies of reactions
III. Operating under a wide range of physical and chemical environments
IV. Substrate specific via induced fit and allosteric regulations
A. I & III
B. II & IV
C. I, II & III
D. II, III, & IV
E. I, II, III & IV

Back 140

Correct Answer: B

Explanation for INCORRECT descriptions:

I. A catalyst will never affect the position of a chemical equilibrium. It will nevertheless speed up both the forward and reverse reactions as the system is tending toward an equilibrium state.

III. Enzymatic activities are environment sensitive and optimally operate within tight specifications of changing factors like temperature, pH, etc.

Front 141

Which of the following anatomical structures develops from the ectoderm?



A. Nerve cord
B. Notochord
C. Trophoblast
D. Blood vessel
E. Digestive tract

Back 141

Correct Answer: A

Formation of trophoblast precedes the development of a three-layered embryo. The nerve cord, belonging to the nervous system, develops from the ectoderm. While a major portion of notochord and blood vessel develops from the mesoderm, the digestive tract has at least the epithelial layer developed from the endoderm.

Front 142

Which of the following anatomical structures develops from the ectoderm?
A. Nerve cord
B. Notochord
C. Trophoblast
D. Blood vessel
E. Digestive tract

Back 142

Correct Answer: A

Formation of trophoblast precedes the development of a three-layered embryo. The nerve cord, belonging to the nervous system, develops from the ectoderm. While a major portion of notochord and blood vessel develops from the mesoderm, the digestive tract has at least the epithelial layer developed from the endoderm.

Front 143

Which of the following divisions do/does NOT belong to kingdom Fungi?
A. Zygomycota
B. Ascomycota
C. Basidiomycota
D. Myxomycota
E. All of the above.

Back 143

Correct Answer: D

Myxomycota (plasmodial slime molds) falls under kingdom Protista. Other easily mistaken counterparts are Acrasiomycota (cellular slime molds) and Oomycota (water molds), simply because of the similar suffix (-cota) appearing in these names. A to C are also commonly and respectively known as the zygote, sac, and club fungi.

Front 144

The ecological efficiency is only 5% from one trophic level to the next. For every 250 J of energy required by the secondary consumers, what is the minimum amount of energy the primary producers will have to generate?
A. 500 J
B. 5,000 J
C. 10,000 J
D. 100,000 J
E. 200,000 J

Back 144

Correct Answer: D

Working backward, the minimum amount of energy mandated among the primary producers will be:

250/(0.05)2 = 100,000 J

Front 145

All of the following factors assist in DNA replication EXCEPT for one. What is that one EXCEPTION?



A. RNA primer
B. DNA polymerase
C. Helicase
D. Nuclease
E. Single strand binding protein

Back 145

Correct Answer: D

A, B, C, and E individually contribute to DNA replication: RNA primer initiates a polynucleotide strand, which is subsequently elongated by DNA polymerase in a 5'g3’ direction; helicase unwinds the parental helix structure into two DNA strands, correspondingly stabilized by the single strand binding protein. Nuclease, on the other hand, appears mostly in the digestive tract (small intestines) and hydrolyzes nucleotides (RNA and DNA) to their respective sugars, phosphates, and bases.

Front 146

Which of the following factors are associated with human blood clotting? I. Protrombin
II. Fibrinogen
III. Calcium
IV. Vitamin E
A. I & II
B. I & III
C. I & IV
D. I, II & III
E. II, III & IV

Back 146

Correct Answer: D

Vitamin K, together with other initial clotting factors like calcium, broken vessels, etc, jointly convert prothrombin into the activated form of thrombin, from which fibrinogen is triggered to fibrin to ultimately trap blood cells in the wounds.

Front 147

Choose the CORRECT descriptions pertaining to the rough endoplasmic reticulum. I. Ribosomes attached on its outer surface
II. Synthesis of secretory glycoproteins
III. Membrane productions
IV. Detoxification of drugs and poisons
A. I, II & III
B. I, II & IV
C. I, III & IV
D. II, III & IV
E. I, II, III & IV

Back 147

Correct Answer: A

Detoxification is generally carried out by enzymes in the smooth endoplasmic reticulum (SER). The liver cells are especially loaded with SER when the body system takes in drugs and/or is poisoned.

Front 148

Sodium-potassium pumps occurring across the membrane of an axon are exhibiting a single mode of



A. passive transport.
B. facilitated diffusion.
C. osmoregulation.
D. diffusion.
E. active transport.

Back 148

Correct Answer: E

Resting potential within an axon is –70 mV resulted by imbalanced [K+] and [Na+] across the membrane. Over the time, this ionic potential dissipates as K+ and Na+ diffuse down their respective concentration gradients. Sodium-potassium pumps therefore serve to maintain the desired potential value by acting against these gradients at the expense of ATP molecules -- a typical characteristic of active transport.

Front 149

Choose the CORRECT statements on gene regulation via a repressible system. I. A repressor is active until it binds to a co-repressor.
II. A repressor is inactive until it binds to a co-repressor.
III. Transcription resumes in the absence of co-repressors.
IV. Transcription resumes in the presence of co-repressors.




A. I & II
B. I & III
C. I & IV
D. II & III
E. II & IV

Back 149

Correct Answer: D

Under a repressible system, the associated proteins (end products) are usually produced continuously until the amount of such proteins formed exceeds a desired (threshold) limit. Acting as co-repressors now, the end products accumulated will begin binding to the repressors to jointly stop the ongoing transcription.

Front 150

O2 affinity of hemoglobin



A. is unaffected under all physiologic circumstances.
B. increases when the blood pH is low.
C. decreases when exchanging for gases at the aveoli.
D. is not regulated by subunit cooperativity.
E. decreases in the presence of carbonic acids known as the Bohr shift effect.

Back 150

Correct Answer: E

Blood pH level coupled by subunit cooperativity basically determines O2 affinity of hemoglobin. At lower pH value (higher concentration of CO2), hemoglobin will more readily unload O2 to surrounding cells and vice versa.

Front 151

Which of the following accounts relate(s) to proton pumps?



A. They are associated with oxidative phosphorylations.
B. Hydrogen ions are pumped from the matrix into the intermembrane space via chemiosmosis in mitochondria.
C. Hydrogen ions are pumped from the stroma into the thylakoid space via chemiosmosis in chloroplasts.
D. They can indirectly drive the active transport of other solutes via cotransport.
E. All of the above.

Back 151

Correct Answer: E

Proton pumps (being powered by exergonic reactions such as ATP depletions, electron transport chain redox series, etc...) commonly function as intermediary to drive other useful processes via the generated proton motive force (H+ gradient) across each cell membrane. A to C are part of the energy couplings enabling the synthesis of ATP in mitochondria and chloroplasts. The presence of transport proteins is required to facilitate both active transport and cotransport.

Front 152

The following membranes develop into the placenta and the umbilical cord EXCEPT for one. What is that one EXCEPTION?



A. Vitelline membrane
B. Yolk sac
C. Amnion
D. Chorion
E. Allantois

Back 152

Correct Answer: A

Vitelline membrane is an outer layer positioned closest to the plasma membrane of a fertilized zygote. It is usually and fully detached from the zygote upon the first mitotic division. Extraembryonic membranes consisting of B to E appear during and/or past the gastrulation stage.

Front 153

Which of the following protists move by pseudopodia?



A. Amoebas
B. Typanosomas
C. Parameciums
D. Plasmodiums
E. Euglenas

Back 153

Correct Answer: A

B and E are flagellated whereas parameciums are ciliated. Plasmodiums, the malaria-causing parasites, move by sliding along the bloodstreams of infected hosts.

Front 154

Which of the following accounts best describes an exponential growth in a population?



A. Its birth rates exceed its mortality rates.
B. It has reached its carrying capacity.
C. It exhibits density dependent effect.
D. It exhibits density independent effect.
E. It is K-selected.

Back 154

Correct Answer: A

Exponential growth, as characterized by decreased mortalities and inflated birthrates, has best been represented by A. B and E are wrong as these exhibit zero growth in a population. Theoretically, an exponential growth is unrestrained, rendering C and D inappropriate as well.

Correct Answer: A

Exponential growth, as characterized by decreased mortalities and inflated birthrates, has best been represented by A. B and E are wrong as these exhibit zero growth in a population. Theoretically, an exponential growth is unrestrained, rendering C and D inappropriate as well.

Front 155

Which of the following factors assist(s) in transcription?



A. Promoter
B. Transcription factor
C. Transcription initiation complex
D. RNA polymerase
E. All of the above

Back 155

Correct Answer: E

Promoter specifies which DNA strand to be used as template prior to determining the starting point of transcription. Transcription factor facilitates binding of RNA polymerase to the promoter, and forming of the crucial transcription initiation complex that kicks off rest of the transcribing process.

Front 156

Antibodies are secreted by



A. memory B cells.
B. plasma cells.
C. memory T cells.
D. cytotoxic T cells.
E. helper T cells.

Back 156

Correct Answer: B

Antibodies secreted by plasma cells in the humoral immune response agglutinate antigens upon binding themselves at the matching receptors. This renders the antigens more susceptible to attack (e.g. phagocytosis) by white blood cells.

Front 157

Which of the following molecules constitute the end-product of glycolysis?



A. Pyruvates
B. Glyceraldehyde phosphates
C. Phosphoenolpyruvates
D. Fructose 6-phosphates
E. Glucoses

Back 157

Correct Answer: A

In glycolysis, each glucose is degraded to two molecules of pyruvates via a series of steps involving many others like D, B and C.

In the presence of oxygen, pyruvate molecules enter the pathway of aerobic respiration entailing both the Krebs cycle and the electron transport chain. When devoid of oxygen, fermentation takes place where ethanols, lactic acids, etc, are formed depending on the type of metabolic pathway involved.

Front 158

The following statements on photosynthesis are true EXCEPT for one. What is that one EXCEPTION?



A. A total of 6 Calvin cycles is required to produce one glucose molecule.
B. Of all pigments known, only chlorophyll a is directly involved in the light reactions.
C. Classified as the dark reactions, Calvin cycles may only occur in the absence of light.
D. Light reactions generate ATP and NADPH molecules.
E. Calvin cycles occur in the stroma of chloroplasts.

Back 158

Correct Answer: C

"Dark reactions" simply means reactions may proceed without the need for sunlight. Whether or not light is present, they will resume as long as ATP and NADPH molecules are continuously supplied to the cycles.

Front 159

Choose the CORRECT elongation sequence(s) of translation.



A. Codon recognition > peptide bond formation > translocation
B. Peptide bond formation > codon recognition > translocation
C. Codon recognition > translocation > peptide bond formation
D. Translocation > peptide bond formation > codon recognition
E. All of the above

Back 159

Correct Answer: A

Codon recognition: binding of a tRNA (amino acid bearing) anticodon to the mRNA codon positioned at the A site of a ribosome

Peptide bond formation: between the new amino acid and the growing polypetide (catalyzed by the ribosome)

Translocation: relative moving of the ribosome one codon forward in the 5’g3’ direction along the mRNA

Front 160

What is the final waste product of deamination in the liver prior to its removal from the excretory system?



A. Ammonia
B. Urea
C. Uric acid
D. Cyanide
E. Protein

Back 160

Correct Answer: B

Both ammonia and cyanide are toxic to human body. Uric acid pertains to excretory systems needing heavy water conservation such as those found in birds and certain reptiles. Protein will be too big a molecule to be transported across the glomerulus at the Bowman’s capsule, and moreover, it may never be the product of deamination. Not only is urea an acceptable form of dissolved waste, it is also crucially needed to increase the osmolarity of interstitial fluid at the inner medulla.

Front 161

Cell communication may occur through



A. hormonal signaling.
B. synaptic signaling.
C. signal transduction.
D. cell-cell recognition.
E. all of the above.

Back 161

Correct Answer: E

Descriptions for all modes of cell communication:

Hormonal signaling – one form of distant communication between endocrine glands and target cells via hormones traveling along the circulatory system

Synaptic signaling – one-way local communication via neurotransmitters traveling across the synaptic cleft at a neuromuscular junction or between two neurons

Signal transduction – cellular response to "signal" molecules via an accentuated chain of molecular interactions

Cell-cell recognition – direct communication between two adjacent cells via surface attached molecules

Front 162

The influence of organizers on the development of another group of embryonic cells is a process termed

A. neurulation.
B. implantation.
C. induction.
D. organogenesis.
E. invagination.

Back 162

Correct Answer: C

In induction, specific genes in the target cells are turned on to differentiate these cells into designated tissue type. Invagination occurs during gastrulation while neurulation takes place right after it. Implantation describes how embryo attaches itself to the uterine wall, and organogenesis relates to organs formation during the first trimester of gestation.

Front 163

Which of the following terms distinctly describes the multinucleated cytoplasm of a fungal hypha?

A. Septate
B. Haustoric
C. Mycellic
D. Coenocytic
E. None of the above

Back 163

Correct Answer: D

Coenocytic hypha mechanistically results from ongoing division of nuclei without cytoplasmic division. Septa basically act as perforated cross walls, turning the otherwise unicellular hypha into multicellular form. Haustoria are modified ends penetrating the host tissue for nutrients absorption whereas mycellia are clusters of interwoven hyphae significantly enhancing this process.

Front 164

Evolving of a new species via genetic isolation from within the same geographical region is a process called

A. adaptive radiation.
B. ecological speciation.
C. allopatric speciation.
D. sympatric speciation.
E. morphological speciation.

Back 164

Correct Answer: D

Incorrect speciation modes are explained as follows:

Adaptive radiation – diversely adapted from a common ancestor (related to geographical isolation)
Ecological speciation – adaptation on the basis of location and activity
Allopatric speciation - isolation via geographical barrier
Morphological speciation – separation on the basis of physical measures and outward features

Front 165

Failure of separating any homologous pair of chromosomes during meiosis is an incident related to

A. non-disjunction.
B. independent assortment.
C. sex linked disease.
D. Mendel’s law of segregation.
E. all of the above.

Back 165

Correct Answer: A

Non-disjunction causes genetic disorder resulting in aneuploid and/or polyploid cells formation. Sex linked diseases are usually X-linked unless otherwise stated, where infected fathers are uniquely observed as passing down defective genes to their daughters only. B and D are part of the Mendelian laws.

Front 166

Choose the CORRECT tropic hormones. I. Antidiuretic hormone
II. Adrenocorticotropic hormone
III. Prolactin
IV. Thyroid stimulating hormone

A. I & II
B. I & III
C. I & IV
D. II & III
E. II & IV

Back 166

Correct Answer: E

Tropic hormones are targeted at other endocrine glands where secondary hormones are correspondingly secreted to regulate designated functions in the body. Adrenocorticotropic hormones stimulate the adrenal cortex to produce and secrete steroid hormones, whereas thyroid stimulating hormones stimulate the thyroid gland to produce and secrete triiodothyronines, thyroxines, and calcitonins mostly via negative feedback mechanisms.

Front 167

Cytokinesis occurs in animal cells through the initial appearance of

A. metaphase plates.
B. cell plates.
C. cleavage furrows.
D. mitotic spindles.
E. cell wall vesicles.

Back 167

Correct Answer: C

Metaphase plate is a term adopted to depict the central plane of a dividing cell in metaphase stage. Mitotic spindles are practically invisible at the end of anaphase. B and E pertain to cytokinesis in plant cells.

Front 168

The maximum number of chromosome combinations among the gametes of a diploid organism (2n =10) is

A. 2
B. 4
C. 8
D. 16
E. 32

Back 168

Correct Answer: E

2n = 10 {diploid representation}

n = 5 {haploid representation}

Using multiplication rule,

2n = 25 = 32

Front 169

What physiologic event will take place if both estrogen and progesterone levels remain high in the human female blood for a prolonged period of three months?

A. 28-day menstruation cycle will be observed during this period of time.
B. Ovulation will occur during this period of time.
C. Ovulation will be unlikely via positive feedback inhibition on the release of luteinizing hormones by posterior pituitary.
D. Ovulation will be unlikely via negative feedback inhibition on the release of luteinizing hormones by anterior pituitary.
E. None of the above.

Back 169

Correct Answer: D

High levels of estrogens and progesterones in the blood are usually sustained via preservation of corpus luteum by human chorionic gonadotropins (HCGs) during the first trimester of preganancy. These hormones are particularly needed to maintain and strengthen the uterine walls. And understandably, menstrual cycle ceases during this period of time. Elevated amount of progesterones also inhibits release of luteinizing hormones (LHs) from the anterior pituitary, rendering ovulation through LHs surge unlikely to happen.

Front 170

Crossing over occurs during

A. Prophase II of Meiosis II.
B. Metaphase II of Meiosis II.
C. Telophase II of Meiosis II.
D. Prophase I of Meiosis I.
E. Metaphase I of Meiosis I.

Back 170

Correct Answer: D

Crossing over occurring in Prophase I of Meiosis I involves two non-sister chromatids belonging to two separate but homologous chromosomes.

Front 171

Plants store energy as:
a. glycogen
b. glucose
c. sucrose
d. starch
e. cellulose

Back 171

Answer: D

These answers are types of polysaccharides (except glucose, which is a monomer) which are used as storage material for needed cellular sugars and may also serve as building material for cells or to protect the whole organism. Starch is the storage polysaccharide of plants, consisting entirely of glucose monomers. Glycogen is the animal store, while cellulose is a major component of plant cell walls.

Front 172

Secondary protein structure is charactarized by:
a. interactions between side chains of amino acids
b. the overall structure of the polypeptide chain
c. the coiling or folding of the polypeptide backbone
d. the unique sequence of amino acids
e. the strong covalent bonds called disulfide bridges

Back 172

C

Primary structure of a protein is the sequence of its amino acids. Secondary structure refers to the protein coils and folds resulting in the protein's overall conformation. Tertiary structure consists of irregular contortions from bonding between side chains. Quaternary structure is the sequence of polypeptide chain aggregates to form a functional protein.

Front 173

All living things are composed primarily of:
a. carbon, hydrogen, and nitrogen
b. carbon, oxygen and sulfur
c. carbon, phosphorus and nitrogen

Back 173

E

There are four major atomic components of organic molecules: carbon, oxygen, hydrogen and nitrogen

Front 174

Cellular respiration occurs within the:
a. mitochondria
b. golgi apparatus
c. lysosomes
d. nucleus
e. ribosomes

Back 174

A

The mitochondria is the site of cellular respiration. More specifically, some of the steps of cellular respiration occur within the matrix (between the cristae) while other proteins that function in respiration are built into the inner membrane. Infoldings increase surface area, which increases the productivity of the organelle.

Front 175

The pores of the nuclear envelope serve which of the following functions?
a. it allows proteins to move into the nucleus
b. it allows ribosomal components to exit the nucleus
c. it allows mRNA to exit the nucleus
d. A and C
e. A, B and C

Back 175

mRNA conveys genetic messages to the cytoplasm via the nuclear pores. Proteins built in the cytoplasm need to enter the nucleus, and ribosomes built in the nucleus need to exit.

Front 176

Which of the following is the primary activity of the golgi apparatus?
a. It's a catalysis of oxidative reactions
b. It synthesizes mRNA and DNA
c. It breaks down carbohydrates
d. It breaks down lipids and steroids
e. It modifies and packages proteins.

Back 176

E

The golgi apparatus is a center of manufacturing, warehousing, sorting and shipping proteins.

Front 177

In a redox reaction...
a. the oxidizing agent donates electrons
b. the reducing agent accepts electrons
c. the reducing agent is the most electronegative
d. the substance that is oxidized loses energy
e. the substance that is reduced loses energy

Back 177

D

During a redox reaction, the loss of electrons from one substance is called oxidation, and the addition of electrons to another substance is known as reduction. Reduction results in an energy increase on the reduced species. The electron donor is called the reducing agent, while the electron acceptor is the oxidizing agent (which is generally the most electronegative) - The terminology of redox reactions is counter intuitive: adding electrons is called reductions. This is in terms of electric charge - negatively charged electrons added to a cation REDUCE the amount of positive charge on the cation.

Front 178

Fatty acids enter the degradative pathway in which of the following forms?
a. glycerol and glucose
b. glycerol
e. adipose tissue
d. keto acids
e. acetyl CoA

Back 178

Fats are broken down to glycerol and fatty acids. While glycerol enters glycolysis pathways, fatty acids (the majority of fat) are broken down into fragments via beta oxidation entering the Krebs cycle as acetyl CoA. Fats produce more than twice as much ATP as carbohydrates.

Front 179

All of the following are charactaristics of mitosis EXCEPT:
a. mitosis occurs in eukaryote cells
b. during prophase, chromosomes condense
c. homologous chromosomes pair up at the metaphase plate
d. there is no crossover of chromosomes
e. the number of chromosomes remain the same after cell division.

Back 179

C

Mitosis and meiosis differ in a few ways. One difference is that during metaphase of mitosis, the chromosomes align at the center of the cell forming the cell metaphase plate. In Meiosis, metaphase I - homologous pairs (two sets) of chromosomes align at the cell center, and separate during anaphase I.Though metaphase II is similar to mitosis, chromosomes will separate into sister chromatids.

Front 180

All of the following are true about sexual reproduction in plants EXCEPT:
a. all plants exhibit alternations of generations
b. the diploid sporophyte generation produces haploid spores.
c. the haploid spores develop into the diploid gametophyte generation
d. spores are cells that prevent the loss of water
e. meristems provide a source of cells that can develop into an adult plant

Back 180

C

The origin of alternation of generations in plants comes from certain life cycles of algae which exhibit alternation of haploid and diploid generations.

Front 181

During the ovarian ovulation phase, you would expect:
a. an increase in estrogen, followed by a decrease in progesterone
b. an increase in estrogen, followed by a decrease in luteinizing hormone
c. an increase in estrogen followed by a surge in luteinizing hormone
d. a decrease in estrogen followed by an increase in progesterone
e. a decrease in estrogen followed by a surge in luteinizing hormone

Back 181

C

During the ovulation phase, there is an increase in estrogen and a spike in LH which triggers ovulation.

Front 182

A father is heterozygous for blood type A and the mother is heterozygous for blood type B. What percentage of their children would be universal blood carriers?
a. 25%
b. 50%
c. 75%
d. 100%
E. no children could be universal donors

Back 182

A

Do a punnet square: IAi x IBi
Results: 25% IAIB, 25% IAi, 25% IBi, (((25% ii)))

Front 183

The sequence of a piece of DNA has been determined to be 5'-ACCAAACCGAGT-3' - What is the transcribed mRNA of this sequence?

Back 183

C

If DNA is 5-3, mRNA will be 3-5. C is complimentary to G, but U instead of T is complimentary to A.

DNA 5'-ACCAAACCGAGT-3'
RNA 3'-UGGUUUGGCUCA-5'

Front 184

The process whereby mRNA codons are converted into a sequence of amino acids is best known as:
a. transcription of RNA
b. transcription of DNA
c. translation of RNA
d. translation of DNA
e. peptide synthesis of DNA

Back 184

C

During translation, the sequence of codons along a genetic message (mRNA) is decoded, or translated, into a sequence of amino acids making up a polypeptide chain.

Front 185

The embryological origin of the circulatory system, gonads and connective tissue throughout the body are characteristic of which germ layer?
a. ectoderm
b. mesoderm
c. endoderm
d. moruladerm
e. gastroderm

Back 185

Mesoderm: skeletal, muscular, circulatory, excretory, reproductive, epidermal systems. Also lining of body cavity and adrenal cortex.

Front 186

Which is the correct pathway blood flows in humans?

Back 186

heart>aorta>arteries>arterioles>capillaries>veins>heart

Front 187

Which of the following is NOT true concerning erythrocytes?
a. they are the oxygen carrying components of blood
b. they are larger than leukocytes
c. their shape increases their surface area
d. they are formed from stem cells
e. they have no mitochondria

Back 187

B

RBC's originate from stem cells, transport oxygen, are bioconcave disk (which increases S.Area) - mature RBC's also lack nucleii and mitochondria. They generate ATP exclusively through glycolysis. Their efficiency relies upon being a small cell, therefore having a greater total area of plasma membrane in a given volume of blood. Leukocytes are larger in size and fewer in numbers.

Front 188

All of the following are hormones of the anterior pituitary EXCEPT:
a. FSH
b. LH
c. TSH
d. Prolactin
e. ADH

Back 188

The anterior pituitary produces six hormones: GH, prolactin, GnRH, TSH, ACTH, MSH.The posterior pituitary produces ADH and oxytocin.

Front 189

Which of the following statements is NOT true concerning neurons?
a. at rest, the neuron is polarized
b. at rest, the inside of the neuron is more negative than the outside.
c. at rest, the intracellular concentration of K+ is greater than Na+
d. an action potential is generated when the outside becomes less negative
e. the nerve cell body receives both excitatory and inhibitory responses.

Back 189

D

Within a neuron, the principle cation is K+ and the outside has a higher conc. of Na+. There is a balanced resting potention of about -70mV inside the cell due to large organic molecules (proteins, amino acids) creating a membrane potential. The inside is less negative than the outside. An action potential may be generated only when the outside of the cell reaches the threshold potential. Neurons can have both excitatory and inhibitory impulses (EPSP's and IPSP's respectively)

Front 190

Which of the following areas of the brain is INCORRECTLY matched to its function?
a. cerebral cortex: sensory input, motor coordination
b. hypothalamus: sex drive, water balance
c. thalamus: relay from the spinal cord
d. cerebellum: motor balance, eye-hand coordination
e. medulla oblongata: hunter, thirst, temperature control

Back 190

The medulla oblongata contains centers that control several visceral functions. It regulates breathing, heart and blood vessel activity, swallowing, vomiting, and digestion. Hunger, thirst and temperature control are functions of the hypothalamus.

Front 191

Which of the following statements concerning the vertebrate skeleton is INCORRECTLY matched?
I. Ligament: attaches muscle to bone
II. Tendon: attaches bone to bone
III. Origin: point of attachment of muscles to a stationary bone
IV. Insertion: point of attachment of muscles to the moveable end of bone.

Back 191

I and II

Ligaments join join bones together at joins
Tendons attach muscles to bones.

Front 192

What organ produces bile and emulsifies fats?

Back 192

Liver

The liver has a multitude of functions. Some major functions include: SYNTHESIS of nitrogenous wastes, plasma proteins, growth factors, bile (which is responsible for fat emulsification in the small intestine) lipids, and freeze protectant chemicals.

Front 193

Respiration in earthworms can be best described by:
a. carbon dioxide excreting directly through the skin
b. nitrogenous wastes excreted in the form of solid uric acid crystals
c. uric acid accumulating in the malphigian tubules
d. contractile vacuoles specialized for waste excretion by active transport
e. carbon dioxide diffuse from the blood and are continually exhaled

Back 193

A

The skin of an earthworm (phylum annelida) is moist and permeable and functions in excretion as a respiratory organ excreting carbon dioxide. The metanephridium is a type of tubular excretory system. The nephridophore deals with urine and the malphigian tubules remove nitrogenous waste and function in osmoregulation.

Front 194

A dog's urine accidents are cleaned up with a newspaper followed by harsh discipline. The dog hides under the bed any time the newspaper is brought out to read. The dog's behavior illustrates:

Back 194

A

Operant conditioning forms an association between a behavior and a consequence. It is also called response-stimulus or RS conditioning because it forms an association between the response/behavior (urine accident then hiding) and the stimulus/consequence that follows (newspaper, harsh discipline)

Operant conditioning is one type of associated learing that directly affects animal behavior. An animal learns to associate one of its own behaviors wih a reward or punishment and then tends to repeat or avoid behavior (trial-and-error learning)

Front 195

A tick bird on a rhinoceros is an example of what type of symbiotic relationship?

Back 195

Mutualism

Front 196

List the heiarchy of taxonomic naming from largest taxon to smallest

Back 196

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Front 197

Analogous structure are those that are

Back 197

Similar in structure/function but evolved independently (do not share a common ancestor)

Front 198

Which is the correct sequence of events in the origin of life?
I. Formation of photobionts
II. Synthesis of organic monomers
III. Synthesis of organic polymers

Back 198

III, II, I

Front 199

According to endosymbiotic hypothesis, which of the following organelles originated as prokaryotic symbionts?
A. Vacuoles and endoplasmic reticulum
B. Nuclei and thylakoids
C. Chloroplasts and mitochondria
D. Storage vesicles and ribosomes
E. Cristae and Golgi apparati

Back 199

C

The inner membrane of chloroplasts and mitochondria, perhaps derived from the membranes of endosymbiotic prokaryotes, have several enzymes and transport systems that resemble those found on the plasma membranes of modern prokaryotes.

Front 200

When two or more individuals of different species associate where one member is harmed and the other member benefits from the relationship, the releationship is termed:
a. commensalism
b. mutualism
c. parasitism
d. saprophytism
e. insectism

Back 200

C

Parasitism is a harm/benefit association. Commensalism is a benefit/neutral association. Mutualism is a benefit/benefit association. Saprophytism relates to organisms that feed on detritus (aka detritovores)

Front 201

Animals represented by general Ascaris and Turbatrix display a unique attribute of movement which is:
a. the use of compound cilia and cirri
b. the peristalic motions of circular muscles
c. the use of circular muscles only
d. the use of longitudinal muscles only
e. the use of pseudopodia

Back 201

D

The genera ascaris and turbatrix display a unique attribute of movement or locomotion which is the use of longitudinal muscles only. The arrangement of protein fibers in the cuticle allow for changes in the length of the worm but not its diameter. This results in the characteristic dorso-ventral thrashing motion that can be translated to efficient forward movement in a visvous medium or an environment with solid or resistant surfaces to push against.

Front 202

A true-breeding tall red flowering plant is (TTRR) is crossed with a true breeding, white dwarf plant (ttrr) What are the phenotypes and ratios found in the F2 generarion?

Back 202

9 tall red
3 tall white
3 dwarf red
1 dwarf white

Dihybrid cross results in a 9:3:3:1 ratio

Front 203

Which of the following best describes regulation and expression in an inducible system?
a. the repressor binds to the operator, forming a barrier that prevents genes from being transcribed
b. the repressor is inactive until it combines with the corepressor, allowing genes to be transcribed
c. the inducer-repressor binds to the operator, allowing genes to be transcribed
d. the repressor-corepressor binds to the operator and represses enzyme synthesis
e. regulation is in a constant state of transcription

Back 203

A

In the inducible system a specific small molecule, called an inducer, inactivates the repressor (which is naturally an active protein) in gene regulation. For the lac operon, the inducer is allolactose. When combined with the repressor it changes conformation of the repressor protein and renders it inactive. When allolactose inactivates the repressor, the lac operon is then able to produce mRNA for enzymes in the lactose pathway.

Front 204

The opening diameter of the eye (pupil) is controlled by what structure?

Back 204

Iris

The anterior choroid forms the donut shaped iris, which gives the eye its color. By changing the size, the iris regulates the amount of light entering the pupil, the hole in the center of the iris.

Front 205

Gas exchange in humans between the lungs and the circulatory system occurs across the...

Back 205

Alveoli

Front 206

Which of the following is NOT true of oxidative phosphorylation
a. it involves the electron transport chain
b. it involves redox reactions
c. it produces approximately three ATP for every NADH that is oxidized
d. the ultimate electron donor is oxygen
e. it depends on chemiosmosis

Back 206

D

Chemical energy harvested from food is transformed to a proton-motive force, a gradient of H+ ions across the membrane. Oxidative phosphorylation is named as such because it is driven by the exergonic transfer of electrons from food to oxygen.

Front 207

WHich of the following is NOT true concerning mitosis?
a. during anaphase, the chromosomes separate and move to opposite poles of the cell.
b. the spindle apparatus disappears during anaphase
c. the nulear membrane begins to dissolve during prophase
D. chromosomes condense, shorten and coil during prophase
E. chromosomes align during metaphase

Back 207

B

Front 208

Which of the following biomes is incorrect
A. desert: widely scattered shrub, cacti, succulents
b. taiga: coniferous forests
c. temperate forest: broad leaved decidious trees
d. tundra: low shrubby or matlike vegetation
e. chapparral: tropical grasses and forms

Back 208

E

Chapparral is charactarized by dense, spiny shrubs with tough evergreen leaves. Their arid climates, short growing seasons, low nutrient soil and frequent fires results in the abundance of limited shrubby vegetation.

Front 209

One of the primary differences between plant cells and animal cells is that plant cells contain:

Back 209

Chloroplasts, cell walls, large vacuoles

Front 210

Which of the following is found in a prokaryotic cell?
a. mesosomes
b. lysosomes
c. ribosomes
d. nucleus
e. A and C

Back 210

E

Prokaryotes' only organelles are the ribosome, the nucleoid, the plasma membrane and the mesosome, which are invaginations of the plasma membrane.

Prokaryotes do not contain a membraned nucleus or lysosomes as eukaryotes do.

Front 211

Amylases are secreted by:
a. pancreas
b. salivary glands
c. large intestine
d. A and C
e. A and B

Back 211

E

Salivary amylase is secreted by the salivary glands and pancreatic amylase is secreted by the pancreas.

Front 212

Which statement(s) is/are correct?
a. Angiosperms include monocots and dicots
b. Cambium tissue cannot develop into xylem or phloem
c. Gymnosperms are the flowering plants
d. Nontracheophytes contain vascular tissue
e. Two of the above

Back 212

A

- Angiosperms are the flowering plants: divided into monocots (narrow leaves, ie. grass) and dicots (broad leaves, ie. shrubs)
- undifferentiated cambium develops into xylem and phloem (vascular tissue)
- Plants lacking vascular tissue are called non-tracheophytes (simple plants)
- Gymnosperms do not flower (ie. pine trees)

Front 213

Which is true about thylakoids?
a) structural components of the mitochondrial membrane
b) A series of disks stacked on each other that contain pigments needed for photosynthesis
c) structures that control gas exchange
d) Disk-shaped structures that consist of undifferentiated meristem cells
e) Two of the above

Back 213

B

Thylakoids are located within chloroplasts. Thylakoids are the site of the light-dependent reactions in plants and cyanobacteria, which utilize the photosynthetic pigments.

Stomata control gas exchange by opening/closing. The meristem is a region of undifferentiated cells in higher plants that produce branches and flowers.

Front 214

A nucleoside consists of:
a) phosphate and base
b) sugar and base
c) phosphate sugar and base
d) phosphate only
e) sugar only

Back 214

B

Nucleosides are the base (A, G, T, C or U) and a sugar (deoxyribose or ribose) - nucleotides are when phosphates become attached to the sugar

Front 215

In the reaction (Glucose --> Glucose-6-phosphate) what enzyme acts as the catalyst?
a) isomerase
b) kinase
c) phosphatase
d) lyase
e) dehydrogenase

Back 215

B

Kinases transfer phosphoryl groups (the enzyme that catalyzes this reaction is called hexokinase)

Isomerases rearrange molectules into different constitutional isomers. Phosphatase cleaves a phosphate ester bond. Lyase cleaves C-C, CO and C-N bonds by elimination. Dehydrogenases participate in redox reactions.

Front 216

Which is true about hemoglobin?
a. It is an allosteric molecule
b. Contains a prosthetic group called a heme.
c. exists as a tetramer
d. Binds CO with a much greater affinity than O2
e. All of these

Back 216

E

- allosteric molecules contain more than one binding site
- oxygen, carbon dioxide, carbon monoxide, and protons bind to the heme group, which contains an iron molecule.
- it is a tetramer, two alpha and two beta subunits, each containing a heme group

Front 217

Platelets are derived from:

a) megakaryocytes
b) leukocytes
c) reticulocytes
d) eosinophils
e) monocytes

Back 217

A

Platelets arise from large, multinucleated cells in the red marrow caled megakaryocytes

Front 218

Stem elongation and flowering in some plants are due to:
a) gibberellins
b) cytokinins
c) abscisic acid
d) ethylene
e) B and D

Back 218

A

Gibberellins are plant hormones that may induce certain plants to flower as well as allow stem elongation.

- Ethylene stimulates fruit ripening
- Abscisic acid is an inhibitor of plant growth hormones
- Cytokinins are plant hormones involved in promoting cell division

Front 219

Which statement is correct?
a) peroxisomes convert hydrogen peroxide into H2O and O2
b) collagen consists of a double helix and is an abundant fibrous protein
c) gluconeogenisis is the reverse of glycolysis
d) centrioles and chloroplasts are found in plant cells

Back 219

A

Peroxisomes convert peroxide into water and oxygen gas.

- collagen is a triple helix
- gluconeogenesis is not the exact reverse of glycolysis. Gluconeogensis can convert non-carbs (fats and AA's) into glucose
- centrioles are not found in plant cells

Front 220

Which statement is true?

a) during anaphase the nucleolus reappears
b) cytokinesis occurs during metaphase
c) centriole separation occurs during prophase
d) spindle fibers begin to form during metaphase
e) two of these

Back 220

C

Centrioles separate and move to opposite poles during prophase (the time when chromatin condenses into chromosomes)

- The nucleolus reappears during telophase
- Cytokinesis occurs during telophase
- Spindle fibers begin to form during prophase

Front 221

A dominant allele has a gene frequency of 0.3. What percentage of heterozygotes is present in this population assuming Hardy-Weinberg equilibrium.
a) 42%
b) 30%
c) 70%
d) 58%
e) 22%

Back 221

A

p = 0.3

1 = p + q = p + 0.3
q = 0.7

from HW equation: 1 = p^2 + 2pq + q^2 =
freq of heterozygotes = 2pq = 2*0.3*0.7 = 0.42

42% are

Front 222

Which statement is false:
a) prokaryotes reproduce by binary fission
b) blue-green algae are found in kingdom plantae
c) circular DNA molecules that exist in the bacterial cells are called plasmids
d) multiple DNA copies can be made by the PCR technique, developed 1983 by Kary Mullis
e) the most accurate way to work out molecular structures is by X-ray diffracation.

Back 222

B

Blue-green algae are prokaryotes of the kingdom bacteria.

Front 223

Which statements is/are true?

a) integral proteins are released by increases in salt concentration
b) reagents such as detergent will cause the release of integral proteins
c) integral proteins are usually not associated with lipids
d) peripheal proteins are usually insoluble in aqueous media.
e) two of the above.

Back 223

B

- peripheal proteins are usually bound to the charged polar head group of the bilayer. Mild treatment with salts removes peripheal proteins.
- Integral proteins, those between the bilayer, need a more severe treatment such as detergent, organic solvents or ultrasonic vibrations.
- peripheal proteins are water soluble, while integral proteins are more soluble in hydrophobic, non-polar solvents.

Front 224

Which statements are false?
a) peptidoglycans are macromolecules found in prokaryotes only.
b) Many viruses that infect bacteria bind to Teichoic Acid chains as a means of cell attachments
c) blue green algae contain cell walls
d) A and B only
e) all are true

Back 224

E

peptidoglycan is found in gram-negative prokaryotes (gram negative because they are not stained via gram staining - they appear purple after the stain)

Techoic acids are the recognition and binding sites for bacterial viruses.

Blue-green algae AKA CYANOBACTERIA, have peptidoglycan cell walls.

Front 225

Which pair is correctly matched?
a) myelin sheath production: Schwann cell
b) Gluconeogenesis: mitochondrial reaction
c) Nerve signal sequence: presynaptic cell -> post-synaptic cell -> synaptic cleft
d) inner ear: cochlea and semicircular canals
e) two of the above

Back 225

E

- myelin is an insulational structure caused by the schwann cell wrapping a plasma membrane many times around the axon.
- Gluconeogenesis is a cytoplasmic reaction, not a mitochondrial one.
- The nerve signal is Presynaptic -> cleft -> postsynaptic
- middle ear: incus, malleus, stapes bones. Inner ear: cochlea, semicircular canals

==> A and D are correct

Front 226

Which hormone is correctly matched to its site of production?
a) Ant. Pituitary: ADH
b) Post. Pituitary: ACTH
c) Beta Pancreatic Cells: Glucagon
d) Adrenal Cortex: NorEpi
e) Ant Pituitary Gland: Prolactin

Back 226

E

- A is false because ADH (aka vasopressin) is produced by the posterior pituitary
- B is wrong because ACTH is produced by the anterior pituitary
- C is wrong because glucagon is produced by alpha cells
- D is wrong because NorEpi is made by the adrenalmedulla
- Prolactin is made by the AntPit (along with ACTH, HGH, LH, FSH, and TSH)

Front 227

What is true about fungi?
a) they are all eukaryotic
b) Many, but not all are saprophytic
c) they are autotrophic
d) They resemble bacterial cells to a greater extent than human cells
e) A and B only

Back 227

E

Fungi facts:
- are eukaryotic heterotrophs
- Secrete digestive enzymes and then absorb the soluble products of digestion
- Composed of filaments called hyphae; collectively the hyphae are called the mycelium
- can reproduce sexually or asexually
- haploid state predominates, but they do alternate between diploid and haploid (alternation of generations)
- saprophytic, break down remains of living organisms that have died
- immotile; have cell walls
- may attack living matter (athelete's foot)
- More similar to human cells than bacterial cells

Front 228

The position or role that an animal occupies within an ecosystem is called a:
a) habitat
b) niche
c) community
d) population
e) biome

Back 228

B

A niche is the role an organism plays in its community: the way it eats, lives and reproduces.

-the habitat is the physical environment where orgnaisms live
- an interaction between populations is called a community
- A group of organisms of the same species in the same general area and time is a population
- a biome is a geographic region inhabited by a distinct community (ie. tundra, desert, chapparal, etc.)

Front 229

A marathon runner discovers she has athelete's foot. What type of relationship exists between her and the fungus?
a) symbiosis
b) parasitism
c) mutualism
d) commensalism
e) saprophytism

Back 229

B

Symbiosis - any close association between two organisms (mutualism, commensalism, or parasitism)
- parasitism is a +/- interaction
- mutualism is a +/+ interaction
- commensalism is a +/0 interaction
- saprophytism is when organisms feed on dead organic matter

Front 230

Which are correctly matched?
a) arthropods: grasshopper
b) annelid: earthworm
c) apoptosis: cell death
d) morula: solid ball of cells
e) all are correct

Back 230

E

- arthropods have jointed legs, exoskeletons, open Circ. system, bilateral symmetry. Resp system consists of spiracles and tracheal tubes.
- Annelids have true coeloms (body cavity) closed circ. system
- apoptosis is programmed cell death

Front 231

Which stomach cell produces pepsinogen?
a) chief cells
b) parietal cells
c) mucous cells
d) G cells
e) delta cells

Back 231

A

Chief cells: secrete pepsionogen (pepsinogen is made into pepsin by HCl)
Parietal cells: secrete HCl and intrinsic factor (B12 absorption)
G-cells: secrete gastrin (stimulates HCl production by parietal cells)
Mucous cells: secrete mucous that lubricates the stomach and protects stomach walls from HCl

Front 232

Which embryonic layers will develop molars, premolars and canines
a) endoderm
b) ectoderm
c) mesoderm
d) B and C
e) Placenta

Back 232

The teeth, along with the skin, hair, eyes and nervous system

Front 233

Which statement is false?
a) the duck-billed platypus is a mammal but does not develop its young internally
b) cartilaginous fish include sharks
c) the chordates have a notochord as well as paired gill slits during embryonic development
d) sea stars and sea urchins have bilateral symmetry and are found in phylum Echinoderma
e) All of these

Back 233

D

Echniderma have radial symmetry. The rest of the choices are true.

Front 234

Which statement is true?
a)osteoclastic cells will secrete collagen and form bone
b) spongy bone is denser than compact bone
c) osteoblasts are able to carry out mitosis
d) smooth muscle and cardiac muscle are mononucleated
e) all of these
e)

Back 234

B

- Osteoclasts break down bone and collagen, and release calcium into the blood. Osteoblasts build bone by absorbing Ca2+ in the blood.
- neither osteoblasts or osteoclasts carry out mitosis; they are produced from stem cells
- cardiac muscle is multinucleated

Front 235

Match the hormone to its function:
a) cortisol: increases blood glucose
b) aldosterone: increases sodium and chloride absorption, K+ secretion
c) Epinepherine: vasoconstriction of blood vessels
d) PTH: increases blood calcium

Back 235

E

All are correct

Front 236

Which statement is false?
a) Calcitonin stimulates osteoclastic activity
b) ADH and vasopressin are made by the hypothalamus and stored in the post. pituitary
c) ADH may increase BP b/cit allows the collecting ducts of the kidney to be more permeable to water
d) the adrenal medulla synthesizes adrenaline and noradrenaline
e) thyroxin increases the basal metabolic rate

Back 236

A

Calcitonin stimulates osteoblastic activity; causes osteoblast to use blood calcium to build bone and collagen... this decreases blood calcium.

The rest are true

Front 237

Which statement is false about a virus?
a) They contain DNA or RNA but never both
b) they are obligate intracellular parasites
c) they are unable to reproduce outside a living cell
d) may use reverse transcriptase to produce an RNA copy from a DNA template
e) the capsid may be spirical or rod-like

Back 237

D

Reverse transcriptase is an enzyme that creates a DNA strand from a the viral RNA template, not the other way around. The rest are true.

Front 238

A colorblind man marries a normal woman. If they have children, what is the probability that their son will be colorblind?
a) 0
b) 0.25
c) 0.5
d) 1
e) 33%

Back 238

A

Punnet square (Xc)(Y) x (XC)(XC)

Girls: all will be heterozygotes, non-affected (carriers)
Boys: all will be normal

Front 239

If a single ancestral species was to evolve into a variety of forms, this would be an example of:
a) convergent evolution
b) genetic drift
c) adaptation
d) adaptive radiation
e) polymorphic variation

Back 239

D

Adaptive radiation is where a number of different species emerge from a single ancestor. This exemplifies divergent evoluton. (ex. Darwin's finches)

- convergent evolution is the evolution of analogous traits (different ancestor, same function/structure)
- genetic drift is the shift in allele frequences due to chance in a non-infinite population
- adaptation is an evolution of a trait to increase fitness
- polymorphic variation is the evolution of distinct forms among a species (ie. male and female)

Front 240

A protein of 210 amino acids is made from how many DNA nucleotides?

Back 240

630

Front 241

Which statement(s) is false?
a) DNA -> mRNA during transcription
b) A sample with a higher A:T ratio will belt lower than one with G:C
c) Down syndrome results from a non-disjunction of Chr. 21
d) meiosis will reduce the chromosome number
e) all are true statements

Back 241

E

- Transcrption is when an mRNA transcript is made from DNA
- If the AT ratio is lower than the GC ratio, the melting point will be lower because there are more H-bond interactions
- meiosis is a reduction of the ploidy

Front 242

Which pair is incorrectly matched?
a) Klinefelter Syndrome: 44 chrom's + XXY
b) Turner Syndrome: Sterile female lacking X chromosome
c) Down syndrome: 47 chromosomes
d) Hemophilia: sex-linked disorder
e) all are correct

Back 242

E

All are correct

Front 243

Which pair is correctly matched?
a) spermatogenesis: Vas deferens
b) sperm maturation: seminiferous tubules
c) sperm expulsion: vas deferens
d) spermatogenesis: prostate
e) two of the above

Back 243

- Spermatogenesis occurs in the seminiferous tubules.
- Sperm maturation occurs in the epididymus.
- Sperm expulsion occurs in the vas deferens.
- The prostate secretes a slightly basic solution that counters the acidic conditions in the vagina.

Front 244

Which is true of enzymes?
a) alter Keq
b) alter heat of reaction
c) alter energy of activation
d) they may be deactivated by feedback inhibition
e) two of these

Back 244

E

Enzymes decrease activation energy, and may be deactivated by feedback inhibition. They do not alter the equilibrium or the heat of reaction.

Front 245

Which of these is false?
a) acquired charactaristics are not transmitted to progeny.
b) In Canis lupus, canis is the genus, lupus is the species
c) Darwin suggested that variation in traits are due to mutations
d) Finches on the Galapogos islands originated from a single species, then became different species is an example of adaptive radiation
e) early earth had a reducing atmosphere of NH3, H2S and CH4.

Back 245

C

Darwin never explained the molecular or genetic mechanisms that caused variation. That was done later by Mendel.

Front 246

Which statement/s is incorrect?
a) Estradiol and progesterone are secreted by the corpus luteum
b) If fertilization does not occur, the corpus luteum degrades into a polar body.
c) fertilization of the egg normally occurs in the fallopian tubes.
d) HCG prevents the corpus luteum from breaking down
e) more than one statement is incorrect

Back 246

B

When fertilization does not occur, the corpus luteum degenerates into the corpus albicans.

Front 247

Which statement is false?
a) the pH of a lysosome is less than 7
b) a Golgi body lacks a membrane
c) Oocyte development is halted at prophase I of meiosis until a female reaches puberty.
d) Transfer of DNA by a virus is called Transduction.
e) All these statements are true

Back 247

B

Golgi bodies do have membranes.

Oocyte development is halted at the primary Oocyte stage until puberty (meiosis is arrested in prophase I)

Front 248

The initiation of the heart beat is largely controlled by the:
a) bundle of His
b) AV node
c) SA node
d) epinepherine
e) Blood CO2 levels

Back 248

The initiation of the heart beat is controlled by the myogenic cells of the SA node. This causes atrial contraction. The signal is then transmitted to the AV node, then down the bundle of his which stimulates ventricular contraction. Epinepherine and blood CO2 influence heart rate, but do not initiate the heartbeat.

Front 249

Which statement is false?
a) Invertibrates include mollusks, arthropods, annelids and echinoderms
b) An amphioxus is a vertibrate
c) Monkeys, apes and man are all called primates
d) A viviparous mammal is one in which the offspring develop within the uterus.
e) The duck billed platypus is an egg-laying mammal.

Back 249

B

Amphioxus and tunicates are chordates, but not vertebrates

Front 250

The inferior vena cava carries blood from the lower extremities to which part of the heart?
a) left atria
b) right atria
c) left ventricle
d) right ventricle
e) pulmonary trunck

Back 250

B

Right atria

Front 251

Which statement is false?
a) the dark reaction of photosynthesis can occur if there is light.
b) NADPH is needed in the dark reaction of photosynthesis
c) During the dark reaction, CO2 becomes attached to ribulose, which breaks it down to yield 2 molecules of PGAL
d) During the light reaction of photosynthesis, a lower concentration of hydrogen ions are produced within the thylakoids
e) six turns of calvin cycle are required to produce one glucose molecule.

Back 251

A

The dark reactions occur in both the absence and presence of light.

Front 252

Applying the Hardy-Weinberg Law to a trait with two alleles, a scientist calculated a frequency of 0.2 for the recessive allele. What is the frequency of the dominant phenotype.

Back 252

0.96

p + q = 1
p + 0.2 = 1
p = 0.8

Homodom: p^2 = 0.8^2 = 0.64
Hetero: 2pq = 0.8*0.2*2 = 0.32

Dominant phenotype: # of homodoms + heteros: 0.32 + 0.64 = 0.96

Front 253

Which statement/s is true?

a) in prokaryotes, the initiation step of protein synthesis places the initiator codon for the mRNA, usually AUG and f-Met-t-RNA at the proper site on the ribosome
b) The genetic code is universal, with the exception of the ribosome
c) Methionine, not N-formylmethionine is the amino acid used in eukaryotes for initiation during protein synthesis
d) A and C
e) Molecular chaperones have no known functions

Back 253

D

Mitochondria have differences in codon/amino acid assignments. Chaperones assemble protein quatrenary structure.

Front 254

Which of the following compounds represents 'high energy' compounds?
a) phosphoenolpyruvate
b) Acetyl-CoA
c) ATP
d) A and C only
e) all of these

Back 254

E

All of the molecules mentioned have a very negative free energy change with their associated reactions. Therefore, they are all high energy and drive nonspontaneous cell processes.

Front 255

Which hormone stimulates the release of bile?
a) entrogastrone
b) cholecystokinin
c) bilease
d) secretin
e) gastrin

Back 255

B

Cholecystokinin is a hormone released by the cells of the duodenum that stimulates bile release.

Front 256

Which statement is false?
a) chemoreceptors located in the aorta and carotid arteries are involved in blood gas content monitoring
b) a small increase in H+ will decrease breathing rate
c) low blood CO2 partial pressure would decrease breathing rate
d) high blood O2 would decrease breathing rate
e) two of the above

Back 256

B

increase in [H+] means increase in [HCO3-] which means increase in CO2... the blood is become less oxygenated, therefore breathing rate will increase.

Front 257

Which statement is false?
a) the umbilical vein carries oxygenated blood from the placenta to the fetus
b) The ductis venosus allows blood to bypass the fetal pulmonary circulation
c) the foramen ovale allows blood to bypass the pulmonary circulation
d) gas exchange does not occur in the fetal lungs.
e) two

Back 257

B

The ductis venosus allows blood to bypass the fetal liver. C is true... the foramen ovale allows blood to bypass the circulatory circulation.

Front 258

Which statement/s is false?
a) the somatic nervous system contains both sensory and motor neurons
b) The autonomic nervous system contain motor neurons
c) equilibrium and balance are controlled by the cerebellum
d) the corpus callosum is a large, myelinated tract that connects the bases of the cerebral hemisphere.
e) all of the above are true

Back 258

B

The autonomic nervous system consists of the parasympathetic and sympathetic nervous system.

Front 259

Which statement about bone is correct?
a) bone growth occurs at the epiphyseal plates of long bones
b) a ligament will connect bone to bone
c) the axial skeleton includes the arms and legs
d) haversian systems are associated with spongy bones
e) A and B only

Back 259

E

- the axial skeleton will include the skull, vertebra and ribs.
- the appendicular skeleton includes the bones of the arms, legs and pelvis
- ligaments connect bone to bone, tendons connect bone to muscle
- haversian systems are associated with compact bone (blood vessels and nerves pass through bone)

Front 260

Which of the following is correctly matched?
a) class gastropoda: snails
b) class crustacea: crabs
c) class arachnida: scorpion
d) class cephalopoda: squid
e) all of the above

Back 260

E

All of the above are correct.

Front 261

Which is false about the liver?
a) albumin synthesis
b) bile production
c) destruction of worn-out old red blood cells
d) converts nitrogenous waste into urea
e) glucose storage

Back 261

E

glycogen is stored in the liver, not glucose.