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166 Cards in this Set

  • Front
  • Back
The area of a cell between the nucleus and the plasma membrane is called
a. organelle
b. intracellular compartment
c. DNA
d. cytoplasm
e. protein
D
A cellular structure with a specific function is called a(n)
a. protein
b. intracellular compartment
c. cytoplasm
d. organelle
e. DNA
D
Resolving power is
a. the measure of an image's clarity
b. the ability of an optical instrument to show two objects as separate
c. the ability of an optical instrument to estimate the size of an image
d. the ability of an optical instrument to magnify an image
e. both a and b
E
Light microscopes
a. use glass lenses to magnify an image and project the image into the viewer's eye
b. work by reflecting light off the surface of an object being studied
c. cannot resolve detail finer than 100 micrometers
d. can generally magnify objects about 10,000 times without blurring
e. all of the above
A
Which of the following is not found in prokaryotic cells?
a. ribosomes
b. a capsule
c. a nucleus
d. pili
e. a cell wall
C
The nucleoid region of a prokaryotic cell
a. contains the cell's nucleoli
b. separates the cell's DNA from the cytoplasm
c. is surrounded by a nucleoid membrane
d. contains the cell's DNA
e. a, b, and c
D
Cells that lack a membrane-bound nucleus are____cells.
a. animal
b. fungal
c. prokaryotic
d. eukaryotic
e. plant
C
You are told that the cells on a microscope slide are plant, animal, or bacterial. You look at them through a microscope and see cell walls and membrane-bound organelles. You conclude that the cells
a. could be either plant or bacterial
b. are animal cells
c. are plant cells
d. are bacteria
e. could be plant, animal, or bacterial
C
The nucleus of a cell
a. is contained within the nucleolus
b. contains DNA
c. is surrounded by a single layer of membrane
d. is the region of the cell where ribosomes are degraded
e. both b and d
B
Long fibers of DNA and protein are called (a)
a. ribosome
b. lysosome
c. nucleolus
d. chromatin
e. central vacuole
D
During cell reproduction, chromatin coils up into structures called
a. chromosomes
b. ribosomes
c. nucleoli
d. lysosomes
e. peroxisomes
A
Rough endoplasmic reticulum
a. produces hydrogen peroxide
b. is not connected to the membranes of the nuclear envelope
c. is a site of lipid synthesis
d. is covered with ribosomes
e. contains microbodies
D
The Golgi apparatus
a. stores proteins, modifies proteins, and packages proteins
b. strings together amino acids to produce proteins
c. is composed of stacks of membranous vesicles that are continuous with one another
d. forms fats from glycerols and fatty acids
e. is the site of carbohydrate breakdown
A
Lysosomes
a. can destroy harmful bacteria engulfed by white blood cells
b. help to digest worn-out or damaged organelles
c. recycle materials within the cell
d. fuse with food vacuoles to expose nutrients to hydrolytic enzymes
e. all of the above
E
Mitochondria differ from chloroplasts in that
a. mitochondria are not found in plants, whereas chloroplasts are not found in animals
b. mitochondria produce glucose whereas chloroplasts break glucose down
c. mitochondria cdontain three different membrane-bound compartments, whereas chloroplasts contain two
d. mitochondria contain membrane folds called cristae, whereas chloroplasts contain disklike vesicles in stacks called grana
e. mitochondria convert solar energy to chemical energy, whereas chloroplasts convert one fomr of chemical energy to another
D
The function of chloroplasts is
a. intracellular digestion
b. lipid synthesis
c. photosynthesis
d. intracellular transport of proteins
e. cellular respiration
C
The function of mitochondria is
a. lipid synthesis
b. intracellular digestion
c. intracellular transport of proteins
d. cellular respiration
e. photosynthesis
D
Which of the following is not a true statement about plant cell walls?
a. plant cell walls protect plant cells by forming an impermeable layer around the cell
b. wood is primarily composed of plant cell walls
c. plant cell walls consist of cellulose fibers embedded in a matrix of polysacharides and proteins
d. the cell wall of one plant cell is separated from the cell wal of another by a later of sticky polysaccharides
e. plant cell walls are multilayered structures
A
All cells on Earth
a. have DNA as the genetic material
b. are enclosed in a membrane that maintains internal conditions different from the surroundings
c. can interconvert chemical materials
d. can interconvert forms of energy
e. all of the above
E
Organelles that contain DNA include
a. ribosomes
b. mitochondria
c. chloroplasts
d. only b and c are correct
e. a, b, and c are correct
E
A plasma membrane is
a. a feature of all cells
b. found in prokaryotes only
c. found in eukaryotic cells only
d. found in plant cells only
e. found in animal cells only
A
Ribosomes are
a. a feature of all cells
b. found in prokaryotes only
c. found in eukaryotic cells only
d. found in plant cells only
e. found in animal cells only
A
Golgi bodies are
a. a feature of all cells
b. found in prokaryotes only
c. found in eukaryotic cells only
d. found in plant cells only
e. found in animal cells only
C
What helps to recycle the cell's organic material?
a. lysosome
b. tonoplast
c. mitochondrion
d. Golgi apparatus
e. peroxisome
A
Where is the site of cellular respiration?
a. lysosome
b. tonoplast
c. mitochondrion
d. Golgi apparatus
e. peroxisome
C
Calculate the surface area to volume ratio of a cube with a volume of
a. 2.5 x 2.5 x 2.5
b. 1.5 x 1.5 x 1.5
S:V
S = 6(lxw)
V = lxwxh

a. 2.4:1
b. 4:1
Life is organized in a hierarchial fashion. Which of the following sequences illustrates that hierarchy as it increases in complexity?
a. organism, organ system, tissue, population, organ, community, cell, ecosystem, molecule
b. cell, molecule, organ system, organ, population, tissue, organism, ecosystem, community
c. ecosystem, molecule, cell, tissue, organism, organ system, organ, community
d. molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem
e. ecosystem, population, organ system, cell, community, molecule, organ, organism, tissue
D
A hypothesis
a. is a tentative explanation for a specific phenomenon
b. is an explanatory idea that is broad in scope and supported by a large body of evidence
c. is the same as a theory
d. is a widely accepted idea about a phenomenon
e. a, c, and d
A
A scientist performs a controlled experiment. This means that
a. the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data
b. one experiment is performed, bit the scientist controls the variables
c. two experiments are conducted, one differig from the other by two or more variables
d. the experiment is repeated many times to ensure that the results are accurate
e. two experiments are conducted, one differing from the other by only a single variable
E
The role of a control in an experiment is to
a. prove that a hypothesis is correct
b. ensure repeatability
c. provide a basis of comparison with the experimental
d. both b and c
e. all of the above
C
An antibiotic kills 99.9% of a bacterial population. You would expect the next generation of bacteria
a. to die out due to the drastic decrease in population size
b. to be more contagious than the prior generation
c. to be more resistant to that antibiotic
d. to be just as susceptible to that antibiotic as was the previous generation
e. all of the above
C
Which of the following is/are true?
a. ecosystems interact; thus it is possible for events occuring in tropical rainforests to influence North American weather patterns
b. understanding carbon and water cycling is an important aid in the understanding of global climate patterns
c. global warming is related to the destruction of forests
d. CO2 emission is an imporatnt contributor to global warming
e. all of the above are true
E
The five most common elements in living organisms are
a. C, N, O, Na, Cl
b. C, N, O, Ca, Fe
c. C, H, O, Na, Cl
d. C, H, O, Na, Ca
e. C, H, O, N, P
E
Matter
a. occupies space
b. is what life is composed of
c. is composed of elements
d. has mass
e. is all of the above
E
A compound
a. is exemplified by sodium
b. contains two or more elements in a fixed ratio
c. is a solution
d. is a pure element
e. is less common than a pure element
B
The nucleus of an atom contains
a. protons and electrons
b. only neutrons
c. only electrons
d. only protons
e. protons and neutrons
E
The atom sodium contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of the sodium?
a. 22
b. 23
c. 11
d. 0
e. 34
B
When full, the innermost electron shell of an atom contains_____electrons, and the outermost shell contains_____electrons.
a. 2, 8
b. 8, 8
c. 2, 2
d. 4, 8
e. 8, 2
A
What is the fundamental difference between covalent and ionic bonding?
In a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner captures the electron from the other.
The oxygen atoms of each water molecule
a. are more positively charged than the hydrogen atoms
b. are electrically neutral
c. are more electronegative than the hydrogen atoms
d. attract electrons less strongly than hydrogen atoms
e. are attracted to the negatively charged atoms of other molecules
C
The water molecule (H-O-H) is held together by
a. a single covalent bond
b. hydrogen bonds
c. a polar covalent bond
d. a double covalent bond
e. an ionic bond
C
___are weak bonds that are not strong enough to hold atoms together to form molecules but are strong enough to form bridges between molecules.
a. ionic bonds
b. polar covalent bonds
c. anionic bonds
d. covalent bonds
e. hydrogen bonds
E
Water molecules stick to other water molecules because
a. the hydrogen atoms of adjacent water molecules are attracted to one another
b. water molecules are neutral, and neutral molecules are attracted to each other
c. the oxygen atoms of adjacent water molecules are attracted to one another
d. hydrogen bonds form between hydrogen atoms of one water molecule and the oxygen atoms of other water molecules
e. covalent bonds form between hydrogen atoms of one water molecule and the oxygen atoms of other water molecules
D
Why can a glass be filled with water to the point where some of the water is above the rim of the glass, yet the water does not overflow the glass?
a. it is an optical illusion; the water is not actually above the rim
b. the pressure of gravity on the water prevents overflow
c. the polar covalent bonds of water prevent overflow
d. water molecules exhibit cohesion
D
As ice melts,
a. hydrogen bonds are broken
b. covalent bonds form
c. water molecules become less tightly packed
d. the water becomes less dense
e. all of the above
A
A solute is
a. the liquid portion of a solution
b. the substance that is dissolved in a solution
c. usually water in living cells
d. the dissolving agent of a solution
e. a, b, and c
B
A solution with a pH of 7 is
a. weakly basic
b. stronly acidic
c. strongly basic
d. weakly acidic
e. neutral
E
A solution with a pH of 1 is
a. weakly acidic
b. weakly basic
c. strongly acidic
d. strongly basic
e. neutral
C
Household ammonia has a pH of 12; household bleach has a pH of 13. Which of the following statements is/are true?
a. both of these substances are strong acids
b. the ammonia has 10 times as many H+ ions as the bleach
c. a solution that could buffer the bleach and ammonia would remove excess OH- ions
d. the ammonia has 10 times as many OH- ions as the bleach
e. both b and d are true
B
In the equation 2H2+O2-->2H20 the H2 molecules are___and the H20 molecules are___.
a. products...reactants
b. reactants...reactants
c. products...products
d. reactants...products
e. none of the above
D
Which of the following is not a characteristic of chemical reactions?
a. chemical reactions involve the making and breaking of chemical bonds
b. the atoms of the reactants are exactly the same as the atoms of the products
c. some chemical reactions create electrons; others destroy them
d. the reactants contain the same number of atoms as products
e. although the atoms of a reaction's reactants and products are identical to each other, their molecular formulas differ
C
Oxygen has an atomic number of 8. Therefore it must have
a. 8 protons
b. 8 electrons
c. 8 neutrons
d. only a and b are correct
e. a, b, and c are correct
D
What do atoms form when they share electron pairs?
a. molecules
b. aggregates
c. ions
d. isotopes
e. elements
A
How do isotopes differ from each other?
a. number of electrons
b. number of protons
c. number of neutrons
d. ability to form ions
e. valence electron distribution
C
How many electrons would be expected in the outer energy level of an atom with atomic number 17?
a. 8
b. 17
c. 2
d. 7
e. 5
D
The science of heredity is referred to as
a. genetics
b. karyotyping
c. a breeding program
d. inheritance
e. none of the above
A
Biologists of the early 19th century believed which of the following?
a. hereditary naterials contributed by the male and female parents blend to form the offspring
b. inheritance is spontaneous event occuring strictly by random
c. traits developed over the lifetime of the parents will be passed to the offspring
d. offpsring inherit the traits of either their mother or their father, not both
e. none of the above
A
Which of the following researchers discovered fundamental principles of genetics by breeding garden peas?
a. Hippocrates
b. Watson and Crick
c. Mendel
d. Jenner
e. Krebs
C
A monohybrid cross is
a. a breeding experiment in which the parental varieties have only one trait in common
b. the second generation of self-fertilized plant
c. a triploid plant that results from breeding two very different plants
d. a breeding experiment in which the parental varieties differ in only one trait
e. none of the above
D
When a gene for a given trait comes in alternative versions that specify different forms of the trait, the versions of the gene are called
a. loci
b. alleles
c. supergenes
d. gametes
e. chromosomes
B
An organism with two different alleles for a single trait is said to be
a. homozygous
b. cross-fertilized
c. genotypically similar
d. heterozygous
e. segregated
D
The expressed or physical traits of an organism are referred to as its
a. genotype
b. expressed form
c. genetic heritage
d. phenotype
e. none of the above
D
The genetic makeup of an organism constitutes its
a. phenotype
b. archetype
c. genotype
d. karyotype
e. autosomal heritage
C
An allele that is fully expressed is referred to as
a. homologous
b. heterozygous
c. recessive
d. dominant
e. none of the above
D
An allele that has no noticable effect on the appearance if an organism unless it is found in a homozygous condition is said to be
a. recessive
b. heterozygous
c. dominant
d. codominant
e. none of the above
A
Alleles of a gene are found at_____chromosomes.
a. different loci on heterologous
b. different loci on homologous
c. the same locus on heterologous
d. the same locus on homologous mitochondrial
e. the same locus on homologous
E
Mendel's principle of independent assortment states that
a. each pair of alleles segregates independently during gamete formation
b. chromosoms sort independently of each other during mitosis and meiosis
c. genes sort independently of each other in animals but not in plants
d. independent sorting of genes produces polyploid plants under some circumstances
e. both a and b
A
What is a testcross?
a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest
Assuming that the probability of having a female child is 50% and the probability of having a male child is also 50% what is the probability that a couple's first-born child is female and second-born child is male?
a. 50%
b. 75%
c. 100%
d. 25%
e. more information is needed to answer the question
D
Persons who are heterozygous for sickle-cell disease are also
a. resistant to African sleeping sickness
b. susceptible to many forms of cancer
c. resistant to malaria
d. resistant to many forms of cancer
e. susceptible to malaria
C
Genes located close together on the same chromosome are referred to as____genes and generally____.
a. homologous...are inherited together
b. linked...do not sort independently during meiosis
c. linked...sort independently during meiosis
d. associated...sort independently during meiosis
e. codependent...do not sort independently during meiosis
B
What is the normal complement of sex chromosomes in a human male?
a. XY
b. XX
c. Y
d. YY
e. XXY
A
How many sex chromosomes are in a human gamete?
a. 2
b. 5
c. 4
d. 3
e. 1
E
Why are sex-linked conditions more common in men than in women?
a. men acquire two copies of the defective gene during fertilization
b. men need inherit only one copy of the recessive allel for the condition to be fully expressed
c. women must inherit two copies of the recessive allel for the condition to be fully expressed
d. the sex chromosomes are more active in men than in women
e. both b and c
E
What is a genetic cross called between an individual of unkown genotype and a homozygous recessive?
a. a hybrid cross
b. a self-cross
c. a testcross
d. an F1 cross
e. a dihybrid cross
C
In crossing a homozygous recessive with a heterozygote, what is the chance of getting an offspring with the homozygous recessive phenotype?
a. 75%
b. 0%
c. 25%
d. 50%
e. 100%
D
In snapdragons, heterozygotes have pink flowers, wheras the two homozygotes have red flowers or white flowers. When plants with red flowers are crossed with plants with white flowers, what proportion of the offspring will have pink flowers?
a. 100%
b. 25%
c. 50%
d. 75%
e. 0%
A
Which of the following is an example of polygenic inheritance?
a. skin pigmentation in humans
b. sex-linkage in humans
c. white and purple color in sweet peas
d. the ABO blood groups in humans
e. pink flowers in snapdragons
A
Characteristics of carbon that contribute to its ability to form an immense diversity of organic molecules include
a. capacity to form single and double bonds
b. ability to bond together to form extensive, branched, or unbranched "carbon skeletons"
c. ability to bond with up to four other atoms
d. tendency to form covalent bonds
e. all of the above
E
Hydrocarbons
a. consist of atoms linked exclusively by single bonds
b. are inorganic compounds
c. contain only carbon and hydrogen atoms
d. are composed of carbon atoms that are attached to hydrogen skeletons
e. all of the above
C
Propanol and isopropanol are isomers. This means they have
a. the same molecular fomula and the same chemical properties
b. different molecular formulas but the same chemical properties
c. the same molecular formula but different chemical properties
d. the same molecular formula, but propanol is the liquid form of the compound and isopropanol is the gaseous form
e. the same number of carbon atoms but different numbers of oxygen and hydrogen atoms
C
Organic compounds
a. can only be synthesized in a labratory
b. always contain nitrogen
c. always contain carbon
d. are synthesized by cells
e. both c and d
E
You now know that the old cliche "oil and water don't mix" is true. Why?
a. oil is hydrophilic
b. oil is an organic compound and water isn't
c. water exhibits polarity and oil does not
d. water is hydrophobic
e. oil exhibits polarity and water does not
C
An -OH group
a. makes a sugar a ketone
b. is found in all sugar molecules
c. makes a protein an aldehyde
d. is also called a carbonyl group
e. none of the above
B
Which of the following statements is/are true of the monomers and polymers found in living organisms?
a. all of the polymers found in all organisms are identical
b. all types of organisms use approximately the same set of monomers to form their polymers
c. each type of organsim has its own polymers, some of which are different from those found in living organisms
a. all of the polymers found in all organisms are identical
b. all types of organisms use approximately the same set of monomers to form their polymers
c. each type of organism has its own polymers, some of which are different from those found in other organisms
d. each type of organism has a unique set of monomers used to form its polymers
e. both b and c are true
E
Monosaccharides can be joined together by a process called dehydration synthesis. Which of the following statements is/are true of this process?
a. one monomer loses a hydrogen atom, and the other loses a hydroxyl group
b. H20 is formed as the monomers are joined
c. covalent bonds are formed between the monomers
d. electrons are shared between atoms of the joined monomers
e. all of the above are true
E
The results of dehydration synthesis can be reversed by
a. polymerization
b. a hydrolysis reaction
c. digestion
d. a condensation reaction
e. both b and c
E
Which list below consists only of molecules that are all polymers
a. sugars, amino acids, nucleic acids, lipids
b. proteins, lipids, nucleic acids, polysaccharides
c. proteins, lipids, nucleotides, sugars
d. proteins, lipids, nucleic acids,sugars
e. polysaccharides, lipids, animo acids, nucleic acids
B
The molecular formula of most monosaccharides is represented as a multiple of
a. CHO3
b. CH3O
c. CHO
d. CH2O
e. CHO2
D
A molecule with the formula C55H110O55 is probably a(n)
a. steroid
b. wax
c. protein
d. polysaccharide
e. oil
D
Sucrose is formed
a. from two glucose molecules
b. from two monosaccharides by a dehydration synthesis
c. when water molecules are added to two monosaccharides
d. when ionic bonds link two monosaccharides
e. a, b, and c
B
Glycogen
a. is a polysaccharide
b. is a carbohydrate animals use to store energy
c. contains C, H, and O atoms
d. contains glucose molecules
e. all of the above
E
Which of the following is not a polysaccharide
a. unbranched starch molecules
b. glycogen
c. cellulose
d. branched starch molecules
e. sucrose
E
Foods that are high in fiber are most likely to be derived from
a. fish
b. meat
c. diary products
d. plants
e. any of the above
D
One way to convert oil into a substance that is solid at room temperature is to
a. add water and shake vigorously
b. put in the regfrigeratior: when unsaturated fats cool, double bonds form and the fats solidify
c. add hydrogens, decreasing the number of double bonds in the molecules
d. remove water, causing a dehydration synthesis reaction to occur
e. remove hydrogens, increading the number of double bonds
C
In salad dressings, oil quickly separates from vinegar because oils are
a. hydrophilic
b. polar
c. amphiphilic
d. nonpolar
e. heavier than water
D
Enzymes
a. function as organic catalysts
b. regulate chemical reactions in a cell
c. have structures that correspond to their function
d. are proteins
e. all of the above
E
Proteins differ from one another because
a. the number of nucleotides found in each protein varies from molecule to molecule
b. the sequence of animo acids in the polypeptide chain differes from protein to protein
c. the peptide bonds linking amino acids differ from protein to protein
d. each protein contains its own unique sequence of sugar molecules
e. the number of nitrogen atoms in each amino acid varies
B
Amino acids can be distinguished from one another by
a. the chemical properties of their R groups
b. the chemical properties of their amino and carboxyl groups
c. the number of R groups found on the amino acid molecules
d. the type of bond between the R group and the rest of the amino acid molecule
e. all of the above
A
Glucose molcules are to starch as____are to proteins
a. fatty acids
b. waxes
c. amino acids
d. oils
e. lards
C
Peptide bonds
a. link amino acids
b. hold the polypeptide chains of complex proteins together
c. form between fatty acids
d. are formed by a hydrolysis reaction
e. none of the above
A
The___structure of a protein consists of a chain of amino acids assembled in a specific order.
a. secondary
b. quaternary
c. tertiary
d. primary
e. none of the above
D
Which of the following is an example of secondary structure protein?
a. a particular amino acid sequence
b. an alpha helix
c. a globular shape
d. a pleated sheet
e. both b and d
E
Nucleotides
a. contain phosphate groups
b. contain nitrogenous bases
c. contain sugar molecules
d. can be linked together to form a double helix
e. all of the above
E
Genetic information is encoded in the
a. sequence of nucleotides in DNA
b. linear sequence of amino acids in a polypeptide
c. length of glycogen
d. quaternary structure of a protein
e. degree of saturation of fatty acids
A
Which, if any, of the following choices does not properly pair an organic compound with one of its building blocks?
a. protein--amino acid
b. fat--fatty acid
c. nucleic acid--glycerol
d. polysaccharide--monosaccharide
e. all of these are paired correctly
C
A new "wonder food" is being distributed by a rival company. The researchers in your company determine that the "wonder food" contains only carbon, oxygen, and hydrogen. At this point, the researchers
a. can say with certainty that the food is not made of proteins
b. can say with cartainty that the food is not made of nucleic acids
c. cannot eliminate the notion that the food may be a fat
d. can say that the food could only be a carbodydrate
e. a and b
E
Glucose and fructose differ in
a. the number of carbon, hydrogen, and oxygen atoms
b. the types of carbon, hydrogen, and oxygen atoms
c. the arrangement of carbon, hydrogen, and oxygen atoms
d. only A and B are correct
e. A, B, and C are correct
C
What is the functional group COOH?
carboxyl
Which property of the carbon atom gives it compatibility with a greater number of different elements than any other type of atom?
a. carbon has 6-8 neutrons
b. carbon has a valence of 4
c. carbon forms ionic bonds
d. only a and c are correct
e. a, b, and c are correct
B
Strictly speaking, the phrase, "like begets like" refers to
a. all forms of reproduction
b. asexual reproduction
c. sexual reproduction
d. production of gametes from a premeiotic cell
e. both a and b
B
Most prokaryotic organisms reproduce mainly by the process of
a. budding
b. binary fission
c. zygote formation
d. production of spores
e. regeneration
B
Sister chromatids are
a. made only of DNA
b. found only when a cell is not actively dividing
c. formed when chromatids separate during cell division
d. unique to prokaryotes
e. tighly linked together at the centromere
E
When a eukaryotic cell is not dividing, its genetic material can be found in the form of very long, thin fibers referred to as
a. RNA
b. the nucleolus
c. chromosomes
d. chromatin
e. the chromatid
D
During prophase of mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called
a. sister chromosomes
b. sister chromatids
c. nucleoli
d. chromatin
e. DNA transcripts
B
The diploid complement of a human somatic cell consists of how many chromosomes?
a. 64
b. 14
c. 23
d. 58
e. 46
E
Eukaryotic cells spend most of their cell cycle in which phase?
Interphase
The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called
Cytokinesis
Which of the following occurs during interphase?
a. growth of aster
b. duplication of chromosomes
c. cell growth
d. all of the above
e. both b and c
E
The phase of mitosis during which the nuclear envelope fragments and the nucleoli disappear is called
Prophase
During which phase of mitosis do the chromosomes line up on a plane located equidistant from the two spindle poles?
Metaphase
Which of the following occurs during mitotic anaphase?
a. the centromeres of each chromosome divide
b. the daughter chromosomes begin to move toward opposite poles of the cell
c. the chromatid DNA replicates
d. sister chromatids separate
e. a, b, and d
E
During which phase of mitosis does the nuclear envelope re-form and the nucleoli reappear?
Telophase
Mature human nerve cells and muscle cells
a. become cancerous more easily than other cell types
b. remain undifferentiated unless an injury occurs
c. continue to divide throughout their lifetime
d. cease dividing after a predetermined number of cell generations
e. are permenantly in a state of nondivision
E
What are all body cells with the exception of sex cells?
Somatic cells
Two chromosomes in a nucleus that carry loci for the same traits in the same position on the chromosome but specify different versions of the same trait constitute a pair of
a. complementary chromosomes
b. homologous chromosomes
c. heterologous chromosomes
d. polyploid chromosomes
e. both a and c
B
In humans, the 22 pairs of chromosomes that don't incluse the sex chromosomes are called
Autosomes
Which of the following is a difference between mitosis and meiosis?
a. In mitosis four daughter cells are produced, whereas in meiosis two daughter cells are produced
b. in mitosis cyokinesis occurs once, whereas in meiosis cytokinesis occurs twice
c. cells produced by mitosis are diploid; cells produced by meiosis are haploid
d. in mitosis two daughter cells are produced, whereas in meiosis four daughter cells are produced
e. b, c, and d
E
During which stage of meiosis does synapsis and the formation of tetrads start?
Prophase I
Which of the following aspects of reproduction enhances genetic diversity?
a. random fertilization
b. independent sorting of homologous chromosomes to daughter cells during meiosis
c. mitosis
d. both a and c
e. both a and b
E
What is the shortest part of the cell cycle?
M
Chromosomes are duplicated during this phase
S phase
The haploid number for a species is 3, each dividing diploid cell will have how many chromatids at metaphase?
a. 18
b. 9
c. 12
d. 6
e. 3
C
All of the following occur during the latter stages of mitotic prophase EXCEPT:
a. the nucleolus disintegrates
b. the nuclear envelope disappears
c. the spindle is organized
d. chromosomes are duplicated
e. the centrioles move apart
D
According to____, energy cannot be created or destroyed.
The first law of thermodynamics
Living systems
a. violate the second law of thermodynamics
b. decrease their entropy while increasing the entropy of the universe
c. violate the first law of thermodynamics
d. both a and b
e. all of the above
B
Which of the following processes is endergonic?
a. the release of heat from the breakdown of glucose
b. cellular respiration
c. the synthesis of glucose from carbon dioxide and water
d. the breakdown of glucose to power ATP formation
e. the burning of wood
C
What is cellular respiration?
the energy-releasing chemical breakdown of glucose molecules and the storage of energy in a form that the cells can use to perform work
What is the basic difference between exergonic and endergonic reactions?
Exergonic reactions release energy; endergonic reactions store it
Anything that prevents ATP formation will
a. force the cell to rely on lipids for energy
b. force the cell to rely on ADP for energy
c. result in cell death
d. have no effect on the cell
e. result in the conversion of kinetic energy to potential energy
C
ATP can be used as the cell's energy currency because
a. endergonic reactions can be fueled by coupling them with the formation of ATP from ADP
b. ATP is the most energy-rich small molecule in the cell
c. endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP
d. the regeneration of ATP from ADP can be fueled by coupling it with exergonic reactions
e. both c and d
E
An energy barrier
a. is higher than the energy of activation of a reaction
b. is the amount of energy that must be produced by the reactants to start a chemical reaction
c. is equivalent to the energy of activation of a reaction
d. prevents the spontaneous decomposition of ATP in the cell
e. both c and d
E
Most of a cell's enzymes are
a. amino acids
b. proteins
c. carbohydrates
d. nucleic acids
e. lipids
B
When an enzyme catalyzes a reaction
a. it acts as a reactant
b. it raises the activation energy of the reaction
c. it becomes a product
d. it lowers the activation energy of the reaction
e. both a and d
D
The active site of an enzyme is_____
The region of an enzyme that attaches to a substrate
Enzyme(s)
a. function depends on its three-dimensional shape
b. are not specific
c. are used up in chemical reactions
d. emerge unchanged from the reactions they catalyze
e. both a and d
E
What is the function of an enzyme?
to catalyze specific reactions
It is important for your temperature to be normal because....
Elevated body temperatures may denature enzymes. THis would interfere with the cell's abilities to catalyze various reactions.
Heating inactivates enzymes by...
breaking the hydrogen bonds that give the molecule its three-dimensional shape
Plasma membranes are selectively permeable. This means that
a. glucose cannot enter the cell
b. plasma membranes must be very thick
c. the plasma membrane regulates the passage of material into and out of the cell
d. anything can pass into or out of the cell
e. cholesterol cannot enter the cell
C
Which of the following is not a function of the plasma membrane?
a. it is the control center of the cell
b. it is involved in self-recognition
c. it forms a selective barrier around the cell
d. it plays a role in signal transduction
e. it has receptors for chemical messages
A
Membrane phospholipids have...
Hydrophilic heads that face outwards and are exposed to water and hydrophilic tails that face the center of the membrane and are shielded from water
Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?
a. Na+
b. CO2
c. a small, nonpolar molcule such as butane
d. H20
e. O2
A
Diffusion does not require the cell to expand ATP. Therefore, diffusion is considered a type of
passive transport
The fluid mosaic model describes the plasma memrbane as consistinf of
a. a phospholipid bilayer with embedded proteins
b. two layers of phospholipids with proteins sandwiched between then
c. a protein bilayer with embedded phospholipids
d. individual proteins and phospholipids that can drift in the membrane
e. both a and d
E
Which of the following is not a true statement about diffusion?
a. it requires no input of energy into the system
b. it proceeds until equilibrium is reached
c. it is driven by entropy
d. it occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated
e. it is a result of kinetic energy of atoms and molecules
D
When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane, and osmosis is allowed to take place, water will
a. exhibit a net movement to the side with highter water concentration
b. not cross the membrane
c. exhibit a net movement to the side with lower water concentration
d. exhibit a net movement to the side with a lower solute concentration
e. exhibit an equal ovement in both directions across the membrane
C
In lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell". The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur?
a. water will eneter the balloon
b. sucrose will leave the balloon
c. sucrose will enter the balloon
d. water will leave the balloon
e. both a and d will occur
D
In lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell". The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. The solution in the balloon is _____ relative to the solution in the beaker.
hypotonic
A cell that neither gains nor loses water when it is immersed in a solution is...
isotonic to its environment
Osmosis can be defined as...
the diffusion of water
Drinking salty seawater would result in...
a. slaking your thirst
b. cells undergoing plasmolysis
c. dehydration
d. cells lysing
e. cells becoming turgid
C
The molecules responsible for membrane transport are
a. carbs
b. proteins
c. ATP
d. steroids
e. phospholipids
B
The ultimate source of nearly all energy available to life on Earth is...
sunlight
Active transport
a. can move solutes up a concentration gradient
b. can involve the coupled passage of solutes
c. requires the cell to expand energy
d. uses ATP as an energy source
e. all of the above
E
Which of the following processes could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than in the surroundings?
a. active transport
b. osmosis
c. facilitiated diffusion
d. diffusion
e. either a or c
A