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241 Cards in this Set

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  • Back
Which of the following statements concerning prokaryotic and eukaryotic cells is not correct?
Prokaryotic cells contain small membrane-enclosed organelles
A new species has been discovered. Individuals of this species are multicellular eukaryotes that obtain nutrients from decomposing organic matter. How should this species be classified?
domain Eukarya, kingdom Fungi
Atoms whose outer electron shells contain eight electrons tend to
be stable and chemically nonreactive, or inert.
What kind of a bond does NH4+ form with Cl- to make ammonium chloride salt (NH4Cl)?
What is the atomic mass of an atom that has 6 protons, 6 neutrons, and 6 electrons?
A(n) ________ refers to two or more atoms held together by covalent bonds.
In a single molecule of water, the two hydrogen atoms are bonded to a single oxygen atom by
polar covalent bonds.
How many molecules of glucose molecular mass =180 daltons) would be present in one mole of glucose?
6.02 × 10^23
The bonds that are broken when water vaporizes are
bonds between water molecules.
The molecular mass of glucose (C6H12O6) is 180 g. To make 1 Liter of a 0.5 M solution of glucose, you should do which of the following?
Dissolve 90 g of glucose in a small volume of water, and then add more water until the total volume of the solution is 1 L.
What property of water is responsible for water transport in plants?
What is the reason why hydrocarbons are not soluble in water?
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages
A molecule with the chemical formula is probably a
Which of the following is not one of the four major groups of macromolecules found in living organisms?
An example of a hydrogen bond is the bond between
the H of one water molecule and the O of another water molecule.
How many electron pairs does carbon share in order to complete its valence shell?
Which is the best description of a carbonyl group?
a carbon atom joined to an oxygen by a double covalent bond
What would be the pH of a solution with a hydrogen ion [H+] concentration of 10^-8 M?
pH 8
At which level of protein structure are interactions between the side chains (R groups) most important?
Which bonds are created during the formation of the primary structure of a protein?
peptide bonds
A polypeptide can best be described as a
polymer of amino acids.
Which of the following statements best summarizes the structural differences between DNA and RNA?
DNA nucleotides contain a different 5-carbon sugar than RNA nucleotides.
The primary structure of a protein is
the amino acid sequence of the polypeptide chain
Which of the following descriptions best fits the class of molecules known as nucleotides?
a nitrogenous base, a phosphate group, and a 5-carbon sugar
In the double helix structure of nucleic acids, Adenine pairs with
Which of the following types of molecules are the main components of cell membranes?
Altering which of the following levels of structural organization could change the function of a protein?
All of the following are part of a prokaryotic cell except
a nucleus
A cell has the following molecules and structures: DNA, ribosomes, plasma membrane, endoplasmic reticulum and mitochondria. It could be a cell from :
a plant or an animal.
Which of the following is NOT considered part of the endomembrane system?
The advantage of light microscopy over electron microscopy is that
light microscopy allows one to view living cells.
Which of the following structure-function pairs is mismatched?
microfilaments (actin filaments) -- cillia & flagella
Which of the following organelles is not a destination for small vesicles that bud off the Golgi apparatus?
Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
smooth endoplasmic reticulum
Which of the following structures is found in an animal cell but not a plant cell?
The function of ribosomes is to
synthesize proteins
Grana, thylakoids, and stroma are all components found in
Cells can be described as having a cytoskeleton of praotein filaments that contribute to the shape, structure, and movement of the cell. All of the following are part of the cytoskeleton except:
the nuclear envelope.
Choose the pair of terms that correctly completes this sentence:
Catabolism is to anabolism as ________ is to ________.
exergonic; endergonic
Which of the following is true for all exergonic reactions?
The reaction proceeds with a release of free energy.
What name is given to the reactants in an enzymatically catalyzed reaction?
An enzyme catalyzes a reaction by
lowering the energy of activation of a reaction.
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as
feedback inhibition
How does a competitive inhibitor inactivate an enzyme?
by binding at the active site of the enzyme
During aerobic cellular respiration, a proton gradient in mitochondria is generated by ________ and used primarily for ________.
the electron transport chain; ATP synthesis
During alcohol fermentation, a key step that allows continual production of ATP is
oxidize NADH to NAD+.
In cellular respiration, the complete oxidation of 1 molecule of glucose generates _______ molecules of ATP.
Organisms that cannot synthesize their own food and must rely on organic molecules from other organisms are callled ?
A human cell containing 22 autosomes and a Y chromosome is...
a sperm
which life cycle stage is found in plants but not animals?
Multicellular haploid
If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis 1 would be
Asexual reproduction and sexual reproduction differ in all but which of the following ways?
Asexual reproduction us utilized only by fungi and protists, whereas sexual reproduction us utilized only by plants and animals
A gene's location along a chromosome is known as what?
What is a karyotype?
A display of every pair of homologous chromosomes within a cell, organized according to size and shape.
The human X and Y chromosomes...
include genes that determine an individual's sex
In animals, meiosis results in gametes, and fertilization results in...
A triploid cell contains three sets of chromosomes. If a cell of a usually diplod species with 42 chromosomes per cell is triploid, this cell would be expected to have what?
63 Chromosomes in 21 sets of 3
Chromatids are separated from each other.
Statement is true for mitosis and meiosis 2.
Homologous chromosomes synapse and crossing over occurs.
The statement is true for meiosis 1 only.
What occurs in meiosis but not in mitosis?
Synapsis of chromosomes
It was important that Mendel examined not just the F1 generation in his breeding experiments, but the F2 generation as well, bcuz...
parental traits that were not observed in the F1 reappeared in the F2
Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except that...
peas have an unusually long generation time
When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype?
a sexually reproducing animal has 2 unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotyoes is possible in a gamete from this organism?
Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. This suggests...
That the parents were both heterozygous.
How many unique gametes could be produced through independent assortment by an individual with the genotype AaBbCCDdEE?
Mendel's observation of the segregation of alleles in gamete formation has its basis in what phases of cell division?
Anaphase 1 of Meiosis
Gene S controls the sharpness of spines in a type of cactus. Cactuses with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cactuses have dull spines. At the same time, a second gene, N, determines whether cactuses have spines. Homozygous recessive nn cactuses have no spines at all. The relationship between genes S and N is an example of...
A cross between a true-breeding sharp-spined cactus and a spineless cactus would produce...
all sharp-spined progeny
2 true-breeding stock of pea plants are crossed. One parent has red, axial flowers and the other has white, terminal flowers; all F1 individuals have red, axial flowers. The genes for flower color and location assort independently. If 100 F2 offspring resulted from the cross, approx. how many of them wld you expect to have red, terminal flowers?
In snapdragons, heterozygous for one of the genes have pink flowers, whereas homozygotes have red or white flowers. When plants with red flowers are crossed with plants with white flowers, what proportion of the offspring will have pink flowers?
What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?
Traits are inherited in discrete units, and are not the results of "blending"
Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of the cross BbTtxBBtt will have black fur and long tails?
What is an example of polygenic inheritance?
Skin pigmentation in humans.
What is the reason that linked genes are inherited together?
They are located close together on the same chromosome.
Red-green colorblindness is a sex-linked recessive trait in humans. 2 people with normal color vision have a color-blind son. What are the genotypes of the parents?
XCxc and XCY
In cats, black fur color is caused by an X-linked allele; the other allele at this locus causes orange color. The heterozygote is tortoiseshell. What kinds of offspring would you expect from the cross of a black female and orange male?
Tortoiseshell females; black males
What is the chromosomal system for determining sex in mammals?
A pedigree analysis for a given disorder's occurrence in a family shows that, although both parents of an affected child are normal, each of the parents has had affected relatives with the same condition. The disorder is then what?
When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to eath other, the F2 generation included both red and white-eyed flies.Remarkably, all the white-eyed flies were male. What was the explanation for this result?
The gene involved is on the X chromosome.
In a cross AaBbCc x AaBbCc, what is the probability of producing the genotype AABBCC?
Mendel accounted for the observation that traits which had disappeared in the F1 generation reappeared in the F2 generation by proposing that...
traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1.
The frequency of Down syndrome in the human population is most closely correlated with which of the following?
Age of the mother
A woman has 6 sons. The chance that her next child will be a daughter is...
Huntington's disease is dominant condition with late age of onset in humans. If one parent has the disease, what is the probability that his or her child will have the disease?
A cross between homozygous purple-flowered and homozygous white-flowered pea plants results in offspring with purple flowers. This demonstrates...
a heritable unit that determines a character and can exist in different forms
An alt. version of a gene
Dominant allele
determines phenotype in a heterozygote
recessive allele
has no effect on phenotype in a heterozygote
the genetic makeup of an individual
an organism's appearance or observable traits
having 2 identical alleles for a gene
having two different alleles for a gene
a cross between an individual with an unknown genotype and a homozygous recessive individual
The oxygen consumed during cellular respiration is involved directly in which process or event?
Accepting electrons at the end of the electron transport chain
What is a chromatid?
a replicate chromosome
Which term describes centromeres uncoupling, sister chromatids separating, ,and the two new chromosomes moving to opposite poles of the cell?
The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction....
loses electrons and loses energy
A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. Those cells would have _____ picograms at the end of the S phase and ______picograms at the end of G2.
Which of the following statements best represents the relationships between the lights reactions and the Calvin cycle?
The light reactions provide ATP and NADPH to the Calvin Cycle and the cycle returns ADP, Pi and NADP+ to the light reactions
The centromere is a region in which
chromatids remain attached to one another until anaphase.
Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei re-forming on eight side of the cell plate. This cell is most likely....
a plant cell in the process of cytokinesis
Which of the following does not occur during the Calvin Cycle?
Release of Oxygen
Chromosomes first become visible during which phase of mitosis?
Where does glycolysis take place?
When oxygen is released as a result of photosynthesis, it is a by-product of which of the following?
Splitting the water molecules
Most CO2 from catabolism is released during....
the citric acid cycle
A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are being absorbed by this pigment?
Blue and violet
What is the reducing agent in the following reaction?
Pyruvate+ NADH+H*--->Lactate+NAD*
The ATP made during glycolysis is generated by....
substrate-level phosphorylation
Which of the following statements best describes the relationship between photosynthesis and respiration?
Photosynthesis stores energy in complex organic molecules, while respiration releases it.
If there are 20 chromatids in a cell, how many centromeres are there?
Which process is most directly driven by light energy?
Removal of electrons from chlorophyll molecules.
in the cells of some organisms, mitosis occurs without cytokinesis. This will result in...
cells with m ore than one nucleus
Which of the following does not occur during mitosis?
Replication of the DNA
The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is....
the H* concentration gradient across the inner mitochondrial membrane.
Which process in eukaryotic cells will proceed normally whether oxygen is present or absent?
How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in G1 of the cell cycle?
The daughter cells have the same number of chromosomes and the same amount of DNA
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?
A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in....
During aerobic respiration, electrons travel downhill in which sequence?
Food->NADH->electron transport chain->oxygen
If a cell has 8 chromosomes at metaphase of mitosis, how many chromosomes will it have during anaphase?
How is photosynthesis similar in C4 and CAM plants?
In both cases, rubisco is not used to fix carbon initially.
What is the term for metabolic pathways that release stored energy by breaking down complex molecules?
catabolic pathways
An organism with a cell wall would have the most difficulty doing which process?
Water passes quickly through cell membranes because
it moves through aquaporins in the membrane
There are 20 different amino acids. What makes one amino acid different from another?
Different side chains (R Groups) attached to an alpha carbon
What is a carbohydrate?
A polysaccharide, disaccharide, monosaccharide, starch.
Choose the pair of terms that correctly completes the sentence: Catabolism is to anabolism as______ is to _______.
Exergonic; endergonic
Which of the following is a characteristic feature of a carrier protein in a plasma membrane?
It exhibits a specificity for a particular type of molecule
Which of the following are nitrogenous bases of the purine type?
Guanine and adenine
On food packages, to what does the term "insoluble fiber" refer?
Which of the following descriptions best fits the class of molecules known as nucleotides?
a nitrogenous base, a phosphate group, and a pentose sugar
Which of the following are capable of converting light energy to chemical energy?
You have a friend that lost 7 kg (abt 15 lbs) of fat on a "low carb" diet. how did the fat leave her body?
It was released as CO2 and H2O
The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is....
Approximately how many molecules of ATP are produced from the complete oxidation of 2 molecules of glucose in cellular respiration?
The light reactions of photosynthesis supply the Calvin cycle with....
Where is ATP synthase located in the mitochondrion?
inner membrane
In a plant cell, where are the ATP synthase complexes located?
Thylakoid membrane and inner mitochindrial membrane
Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center of the cell. These particular cells are in which stage of mitosis?
Protists and bacteria are grouped into different domains because....
protists ave a membrane-bounded nucleus, which bacterial cells lack
Which of the following properties of processes do we associate with living things?
Growth and reproduction, evolutionary adaptations, energy processing, responding to the environment
Which of the following sequences represents the hierarchy of biological organization from the least to the most complex level?
molecule, cell, organ system, population, ecosystem, biosphere
Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
Smooth endoplasts
Which of the following statements regarding enzymes is true?
Enzymes increase the rate of reaction.
which of the following store and transmit hereditary information?
nucleic acids
Enzymes are
The tertiary structure of a protein is the
unique three- dimensional shape of the fully folded polypeptide
In terms of the hierarchical organization of life, a bacterium is at the ______ level of organization, whereas a human is at the _____ level of organization.
Single-celled organism; multicellular organism
Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope?
Which of these is reflective of the hierarchical organization of life from most to least inclusive?
Kingdom, phylum, class, order, family, genus, species
In the term trace element, the modifier trace means...
the element required in very small amounts.
Compared with 31P, the radioactive isotope 32P has....
one more neutron
The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom (6), predict the molecular formula of the compound.
What is true?
a.) the atom has more electrons that protons.
b.) the atom has fewer protons than does a neutral atom of the same element.
c.) the net charge is 12
d.) the atom has more protons than electrons
e.) the atom has more neutrons than protons
A.) the atom has more electrons than protons
The reactivity of an atom arises from....
the existence of unpaired electrons in the valence shell.
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approx. 96% of living matter.
carbon, hydrogen, nitrogen, oxygen
What is the approx. atomic mass of an atom with 16 neutrons, 15 protons and 15 elections?
31 Daltons
A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water, equal to the volume of blood lost, is transferred directly into one of his veins. What will be the most probable result of this transfusion?
The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells.
Which of the following is a compartment that often takes up much of the volume of a plant cell?
Which of the following statements is correct about diffusion?
It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.
If a DNA sample were composed of 10% thymine, what would be the percentage of guanine?
Which of the following metabolic processes can occur without a net influx of energy from some other process?
C6H12O6+6 O2==> 6 CO2 + 6H2O
the covalent chemical bond is one in which....
outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both-atoms.
electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that....
an electron may move to an electron shell farther out from the nucleus.
calcium has an atomic number of 20 and an atomic mass of 40. Therefore, a calcium atom must have....
20 protons
When two atoms are equally electronegative, they will interact to form...
nonpolar covalent bonds.
A covalent bond is likely to be polar when....
one of the atoms charing electrons is much more electronegative than the other atom.
A group of molecular biologists is trying to synthesize a new artificial compound to mimic the effects of a known hormone that influences sexual behavior. They have turned to you for advice. Which of the following compounds is most likely to mimic the effects of the hormone?
A compound with the same 3-dimensional shape as part of the hormone
The bonds that are broken when water vaporizes are....
hydrogen bonds between water molecules
We can be sure that a mole of table sugar and a mole of vitamin C are equal in their....
Number of molecules
Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?
10^-4 M
In a single molecule of water, 2 hydrogen atoms are bonded to a single oxygen atom by....
polar covalent bonds
When chemical. transport, or mechanical work is done by an organism, what happens to the heat generated?
It is lost to the environment
What maintains the secondary structure of a protein?
hydrogen bonds
Cells of the pancreas will incorporate radioactively labeled amino acids into proteins. This "tagging" of newly synthesized proteins enables a researcher to track their location. In this case, we are tracking an enzyme secreted by pancreatic cells. What is its most likely pathway?
ER==> Golgi==> vesicles that fuse with plasma membrane
Which of the following is (are) true for anabolic pathways?
They consume energy to build up polymers from monomers
Which of the following is a diverse group of hydrophobic molecules?
What gives rise to the cohesiveness of water molecules?
Hydrogen bonds
Which of the following effects is produced by the high surface tension of water?
A water strider can walk across the surface of a small pond.
One mole (mol) of a substance is....
6.02x10^23 molecules of the substance and the molecular mass of the substance expressed in grams.
The molecular mass of glucose is 180 g. Which of the following procedures should you carry out to make a ..5 M solution of glucose?
Dissolve 90 g of glucose in a small volume of water, and then add more water until the total volume of the solution is 1 L.
Which of the following solutions has the greatest concentration of hydrogen ions (H*)?
gastric juice at pH 2
which of the following statements is true about buffer solutions?
They maintain a relatively constant pH when either acids or bases are added to them.
Carbon dioxide is readily soluble in water, according to the equation CO2+H2O--> H2CO3 Carbonic acid is a weak acid. Respiring cells release CO2. What prediction can we make about the pH of blood as that blood first comes in contact with respiring cells?
Blood pH will decrease slightly
Which of the following hydrocarbons has a double bond in its carbon skeleton?
Why are hydrocarbons insoluble in water?
the majority of their bonds are nonpolar covalent carbon to hydrogen linkages.
Research indicates that Ibuprofen is a mix of 2 enantiomers; this is, molecules that...
are mirror images of one another
A compound contains hydroxyl groups as its predominant functional group. Which of the following is true concerning this compound?
It should dissolve in water
The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions?
C60 H102 O51
Which structure is common to plant and animal cells?
In animal cells, hydrolytic enzymes are packaged to prevent general destruction of cellular components. Which of the following organelles functions in this compartmentalization?
In the double helix structure of nucleic acids, cytosine hydrogen bonds to
Of the following functions, the major purpose of RNA is to
Function in the synthesis of protein.
The function of each protein is a consequence of its specific shape. What is the term used for a change in a protein's 3-dimensional shape or conformation due to disruption of hydrogen bonds, disulfide bridges, or ionic bonds?
What is true about unsaturated fats?
They have double bonds in the carbon chains of their fatty acids
Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?
a molecule with the formula C18 H36 O2 is probably a....
fatty acid
which structure-function pair is mismatched?
microtubule; muscle contraction
According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly....
embedded in a lipid bilayer
which of the following is present in a prokaryotic cell?
Passive transport includes.....
facilitated diffusion
diffusion of a solute across a membrane
transport of an ion down its electrochemical gradient
which of the following is not a polymer?
if a modern electron microscope can resolve biological images to the nanometer level, as opposed to the best light microscope, this is due to which of the following?
electron beams have much shorter wavelengths than visible light
Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold?
by increasing the percentage of unsaturated phospholipids in the membrane
which of the following types of molecules are the major structural components of the cell membrane?
Phospholipids and proteins
What is the chemical mechanism by which cells make polymers from monomers?
dehydration reactions
What kinds of molecules pass through a cell membrane most easily?
Small and hydrophobic
In Eukaryotic Cells, transcription cannot begin until....
several transcription factors have bound to the promoter
Which of the following is not true of a codon?
it extends from one end of a tRNA molecule
What is true of a codon?
It consists of 3 nucleotides
it may code for the same amino acid as another codon
it never codes for more than one amino acid
it is the basic unit of the genetic code
The anitcodon of a particular tRNA molecule is....
complementary to the corresponding mRNA Codon
Which of the following is not true of RNA processing?
Exons are cut out before mRNA leaves the nucleus.
What is true of RNA processing?
Nucleotides may be added at both ends of the RNA
Ribozymes may function in RNA splicing
RNA splicing can be catalyzed by spliceosomes
A primary transcript is often much longer than the final RNA molecule that leaves the nucleus
Which of the following mutations would be most likely to have a harmful effect on an organism?
A deletion of three nucleotides near the middle of a gene
Which component is not directly involved in translation?
What is directly involved in translation?
In his work with pneumonia-causing bacteria and mice, Griffith found that....
some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic.
E Coli. cells grown on 15N medium are transferred 14N medium and allowed to grow for two more generations. DNA extracted from these cells is centrifuged. What density distribution of DNA would you expect in this experiment?
One low-density and on intermediate density band
A biochemist isolates and purifies molecules needed for DNA replication. When she adds some DNA, replication occurs, but each DNA molecule consts of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mix?
DNA Ligase
What is the basis for the difference in how the leading and lagging strands of DNA molecules are synthesized?
DNA polymerase can join new nucleotides only to the 3' end of a growing strand
In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules?
The elongation of the leading strand during DNA synthesis......
depends on the action of DNA polymerase
The spontaneous loss of amino groups from adenine results in hypoxanthine, an uncommon base, opposite thymine in DNA. What combo of molecules could repair such damage?
Nuclease, DNA polymerase, DNA ligase
In a nucleosome, the DNA is wrapped around....
in his transformation experiments, what did Griffith observe?
Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form.
Cytosine makes up 38% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine?
Which of the following investigators was/were responsible for the following discovery? Phage with labeled proteins or DNA was allowed to infect bacteria. It was shown that the DNA, but not the protein, entered the bacterial cells, and was therefore concluded to be the genetic material.
Alfred Hershey and Martha Chase
What is the function of topoisomerase?
relieving strain in the DNA ahead of the replication fork.
What kind of chemical bond is found between paired bases of the DNA double helix?
It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in which of the following?
sequence of bases
What is mean by the description "antiparallel" regarding the strands that make up DNA?
the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.
What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?
join Okazaki fragments together.
What determines the nucleotide sequence of the newly synthesized strand during DNA replication?
the nucleotide sequence of the template strand.
An Okazaki fragment has which of the following arrangements?
5'-RNA nucleotides-DNA nucleotides-3'
Which of the folling is not an observable or inference on which Darwin's theory of natural selection is based?
Poorly adapted individuals never produce offspring
Systems biology is mainly an attemp to..
construct models of the behavior of entire biological systems
What best demonstrates the unity among all organisms?
the structure and function of DNA
the reactivity of an atom arises from
the existence of unpaired electrons in the valence shells