Bio Quizes
Which most likely represents an example of disruptive selection?
a population of butterflies that are either all yellow or all blue
Which chemical structure is shared by the heme groups of hemoglobin, vitamin B12, and chlorophyll?
a porphyrin ring
What is the role of IP 3 in a signal transduction pathway?
second messenger
Which of the following is a genetic marker that could be linked to a disease through a genome-wide association study?
single nucleotide polymorphisms (SNPs)
Which of the following first binds to the mRNA at the translation initiation site?
small ribosomal subunit
Which of the following cannot be used as a final electron acceptor in anaerobic respiration?
water
Complete the following sentence: A buffer is typically a...
weak acid or a weak base.
Complete the following sentence: The head of a phospholipid is hydrophilic because it has...
a phosphate group
Which specific sequence is important for termination in eukaryotes?
a polyadenylation signal
What is the end product of both binary fission and mitosis
two daughter cells identical to the parent cell
What happens during a phosphorylation reaction?
A kinase catalyzes the removal of a phosphate group from ATP and the bonding of that group to a target protein
Identify the process or processes that require energy.Identify the process or processes that require energy.
***All Answers are correct *breaking chemical *bonds *photosynthesis *movement of molecules transferring energy from one form to another
Which of the following statements about types of experimental setup is correct?
***All of the answers are correct. *A controlled experiment is one in which the experimental group receives the treatment and the control group does not. *A natural experiment is one in which two different natural populations are compared. *A regression analysis experiment is one in which varying levels of treatment are compared. *An active controlled experiment is one in which a new treatment is compared to an old one.
How does cell structure influence how cells react to chemical signals?
*Ion channel-linked receptors, protein kinase receptors, and G protein-coupled receptors are transmembrane receptors. *Hydrophobic molecules bind with cytoplasmic receptors. *Water-soluble molecules bind with receptors situated on the cell membrane. *Large, hydrophilic molecules bind with receptors situated on the cell membrane. ***All answers are correct.
Which of the following correctly describes the sugar component of a nucleotide?
*It is a hexose. *It includes an amine functional group. *It is connected by the 1-position carbon to a phosphate functional group. *** None of the answers are correct.
The somatic cells of a diploid organism have 20 chromosomes. Which of the following statements is/are true?
*Its germ cells have 20 chromosomes. *Its gametes have 10 chromosomes. *After fertilization, the zygote has 20 chromosomes. ***All answers are correct.
Which reason(s) explain(s) why milk is a useful source for isolating genetically modified proteins, such as insulin, from an animal?
*Milk is easy to obtain from an animal. *The animal does not need to be killed to access the protein. *Domesticated animals can be used easily. *Milk is produced in large quantities. *** All answers are compete
Which of the following factors affects how many blood cells a person has?
*contracting an infection *the person's genes *moving to a high altitude *training for a triathlon ***All answers are correct.
Which of the following are post-translational modifications?
*glycosylation *phosphorylation *protein cleavage *multiple polypeptides binding together *** All answers are correct
Disrupting actin function would hinder which of the following?
*movement in amoebae *phagocytosis in amoebae *phagocytosis in macrophages *ingestion in macrophages ***All answers are correct.
Which of these is NOT a component of metabolism?
*photosynthesis *cellular respiration *synthesis of organic *molecules *decomposition ***None of the answers are correct; all of the choices are examples of metabolic reactions/processes.
What result showed up in the F 1 generation of Mendel's first monohybrid crosses that countered prevailing ideas about inheritance?
All the plants looked like just one of the parents.
If a homozygous dominant plant is crossed with a homozygous recessive plant, what proportion of offspring would be homozygous?
0
White eyes in fruit flies are X-linked, with red eyes dominant to white eyes. If you bred a red-eyed, wild-type male with a white-eyed female, what phenotypic ratio would you expect among the offspring?
1 red-eyed female : 1 white-eyed male
How does the base composition of DNA and RNA differ?
Bases in DNA include adenine, cytosine, guanine and thymine. RNA bases include adenine, cytosine, guanine, and uracil.
In a dihybrid cross, when both parents are heterozygous for two genes, what proportion of offspring are predicted to be homozygous dominant for both genes?
1/16
In peas, purple flowers (P) are dominant to white flowers (p). You cross two heterozygous plants with purple flowers and get the expected results in the offspring. If you chose a purple-flowered plant at random from the offspring, what is the chance that it is homozygous?
1/3
If both parents are heterozygous for a trait, what is the probability that a given offspring of theirs will display the recessive trait? Assume the gene for the trait is not sex-linked.
1/4
Fossilized bones are discovered. Carbon dating indicates that they contain one-fourth the normal amount of carbon-14 found in the bones of a living specimen. The half-life of carbon-14 is 5,730 years. Approximately how old are the bones?
12,000 years
During glycolysis, how many molecules of NADH are formed per molecule of glucose?
2
What variable in the Hardy-Weinberg equation expresses the heterozygous genotype?
2 pq
How many different aminoacyl-tRNA synthetases exist?
20
A population survey shows that 160 out of 250 individuals express the recessive phenotype. What percentage of the population would you predict to be heterozygotes?
32%
If the sequence of bases on one strand of the DNA molecule is 5′-CCAGT-3′, what is the corresponding complementary sequence of bases on the other strand?
3′-GGTCA-5′
How many different types of histone subunits are present in a nucleosome?
4
How many autosomal chromosomes are present in an individual with Klinefelter syndrome?
44
The [OH -] of pickle juice is 10 -9 M. What is the pH?
5
A couple's first son is colorblind, though neither parent is. Colorblindness is an X-linked recessive trait. What is the probability that the couple's second son will be colorblind?
50%
Huntington's disease, a progressive nervous system disorder, is inherited as a dominant trait. The songwriter Woody Guthrie died of Huntington's disease. If he was heterozygous for the trait and his wife did not carry it, what was the probability that their son would develop Huntington's disease?
50%
Which of the following sequences could theoretically base pair in a short segment of DNA?
5′-AACGGTA-3′ 3′-TTGCCAT-5′
If the coding strand of DNA has the sequence 5′-CGAGACTTCTGA-3′, what will the sequence of the transcribed RNA be?
5′-CGAGACUUCUGA-3′
Following the entry of carbon dioxide through the stomata, trace the path of carbon dioxide in a C 4 plant by placing these steps in the correct order. 1. Oxaloacetate is converted into malate. 2. Malate is broken down into pyruvate and carbon dioxide. 3. Carbon dioxide enters the Calvin cycle. 4.Malate is transported to the bundle-sheath cells. 5.The compound oxaloacetate is formed. 6.Carbon dioxide reacts with phosphoenolpyruvate
6, 5, 1, 4, 2, 3
A baked potato and a bowl of lettuce are both primarily made up of glucose. Explain why eating the potato gives you lots of calories while eating the lettuce gives you almost none.
A baked potato is primarily starch, a polymer of alpha-glucose, while lettuce is primarily cellulose, a polymer of beta-glucose. Alpha-amylase, an enzyme in your saliva and stomach, can digest starch to release individual glucose molecules but cannot digest cellulose. Therefore, you are able to break down the starch and gain energy, but you cannot break down the cellulose, which passes through your digestive system as fiber.
Why is the G 1 checkpoint particularly important in mammalian cells?
A cell that passes the G 1 checkpoint usually begins the process of cell division.
How does cytokinesis begin in an animal cell?
A cleavage furrow forms.
Which of these observations would provide evidence of independent assortment?
A dihybrid cross yields a 9:3:3:1 phenotypic ratio.
How does a karyotype differ from a family pedigree?
A family pedigree is useful in identifying inherited diseases, but a karyotype is usually not.
How many fatty acids are found in a fat/triglyceride? In a phospholipid? In cholesterolHow many fatty acids are found in a fat/triglyceride? In a phospholipid? In cholesterol
A fat/triglyceride has three fatty acids joined by ester bonds to a glycerol. A phospholipid has two fatty acids joined to glycerol by ester bonds. Cholesterol does not contain any fatty acids.
Which of the following best describes the phenomenon of transformation that Griffith observed in his experiments with different strains of bacteria?
A heritable substance from a strain of dead bacteria caused a change in the characteristics of a living strain of bacteria.
What would happen if a kinase were disabled in a signal transduction pathway?
A target protein would fail to be phosphorylated.
Why is cell size limited?
Because as a cell gets bigger, its volume increases more quickly than surface area. A large cell does not have enough surface area to efficiently move substances in and out.
Why does ATP hydrolysis release a lot of free energy?
ATP is unstable compared to its products.
Which of the following enzymes is not used during the citric acid cycle?
ATP synthase
Who independently formulated the hypothesis of natural selection before Darwin published his work?
Alfred Russel Wallace
Which of the following is an accurate statement about microarrays?
All answers are accurate statements about microarrays.
Which of the following molecules can be used by organisms to obtain energy?
All answers are correct.
How is DNA similar in prokaryotic and eukaryotic cells?
All answers are correct. Both: *DNA is a double helix *DNA contains genetic information on how to make protiens for various life functions *Ribosomes are needed to translate information in DNA into protiens. *DNA is made of the same bases
All polypeptides in eukaryotes have which of the following in common?
All polypeptides start with the same amino acid.
Which statement correctly describes stem cells?
An embryonic stem cell is a cell in an organism that may divide indefinitely and has the ability to differentiate into different types of cells.
Which of the following best describes an essential element?
An essential element is one that is necessary for an organism's survival.
In ocean acidification, the following reaction occurs: CO 2 + H 2O = H 2CO 3 = H + + HCO 3 - = 2H + + CO 3 2- Which of the following statements about ocean acidification is NOT true?
As a result of more CO 2 entering the ocean, the level of CO 3 2- will increase, which will cause CaCO 3 to dissolve.
Why is it advantageous for the Calvin cycle to occur in bundle sheath cells in C 4 plants?
CO 2 levels are high in bundle sheath cells.
Which of the following occurs during the Calvin cycle?
Carbon is reduced and NADPH is oxidized.
Which of the following steps of mitosis occurs first in plants and animals?
The nuclear membrane breaks apart.
Complete the following sentence: A frameshift mutation is one of the most severe types of mutations because...
Complete the following sentence: A frameshift mutation is one of the most severe types of mutations because...
Which of the labeled organelles can be thought of as the "recycling center" of the cell? Identity of organelles: A — mitochondrion; B — rough endoplasmic reticulum; C — smooth endoplasmic reticulum; D — lysosome; and E — Golgi apparatus.
D
How does the first law of thermodynamics apply to metabolic reactions?
Endergonic reactions must be paired with exergonic reactions.
How do enzymes increase the rates of chemical reactions?
Enzymes provide a lower-energy pathway to form the transition state.
What is the advantage of having DNA within a nucleus rather than within the cytoplasm of a cell?
DNA is kept relatively safe within the nucleus of a eukaryotic cell.
What is accomplished during transcription?
DNA transfers information to RNA.
Complete the following sentence: The genes that are passed from generation to generation are stored in...
DNA.
Why is deactivation critical in signal transduction?
Deactivation contributes to control of a signal, allows a signal to sequentially progress down the transduction cascade, and can prevent inappropriate persistence of a transient signal.
Which of the following is a characteristic of direct contact?
Direct contact can facilitate cell-cell recognition.
What is the net result of glucagon binding to a liver cell?
Glucose levels in the blood increase.
Which of the labeled organelles would be most likely to produce vesicles containing substances that will be released by exocytosis? Identity of organelles: A-mitochondrion; B-rough endoplasmic reticulum; C-smooth endoplasmic reticulum; D-lysosome; and E-Golgi apparatus.
E
Which of the following is NOT true of most or all multicellular organisms?
Each cell in a multicellular organism can reproduce to form a new multicellular individual.
If an animal egg were fertilized by many sperm, there would be many copies of the organism's chromosomes in the egg. What prevents this from happening?
Egg activation, which involves biochemical reactions, prevents more than one sperm from entering the egg.
Which of the events below would likely allow the interior of a cell to become more negatively charged?
Either a proton pump begins pumping protons out of the cell or a sodium-potassium pump starts pumping.
Which of the following is NOT a part of cell theory?
Every living organism is made up of many cells.
Which cell cycle phase are most cells of the human body in most of the time?
G 0
In which phase does a normal cell make the commitment to divide or not?
G 1
One codon for asparagine has the sequence AAC. What is the sequence of the anticodon on the aminoacyl-tRNA (in the 5′ to 3′ direction)?
GUU
A family pedigree is useful in identifying inherited diseases, but a karyotype is usually not.
He used experimentation, observation, and mathematical analysis.
Why do histones and DNA bind together?
Histones are positively charged and the phosphate groups in the DNA backbone are negatively charged.
Which characteristic makes it least likely that an organism will be preserved in a fossil?
It lived in a tropical rain forest.
What is suggested by comparing the bones in a human arm and a bat's wing?
Humans and bats share a common ancestor.
Which of the following statements about hydrogen bonding and water is true?
Hydrogen bonding occurs between the hydrogen atom of one water molecule and the oxygen atom of another water molecule.
Which of these processes occurs in the mitochondria? I. Glycolysis II. Citric acid cycle III. Oxidative phosphorylation
II and III
Which of the following is one purpose of using PCR as part of the process of obtaining short tandem repeat results from a sample?
If the quantity of DNA sample is insufficient for analysis, the PCR reaction can amplify it enough for visualization on a gel.
Which observations formed the basis of Darwin's argument for the theory of natural selection explaining descent with modification outlined in On the Origin of Species?
Individuals vary in heritable traits and produce more offspring than are able to survive, and those offspring compete for limited resources.
Which of the following is the mechanism that drives natural selection?
Individuals with traits better suited to their environments are more likely to survive and reproduce; therefore, their offspring are more likely to inherit these adaptive traits.
Why is a self-destruct mechanism adaptive for an organism?
It allows for the replacement of old potentially damaged cells with new ones, and it enables removal of cells without activating inflammation.
Which of the following is a unique property of evolution by gene flow?
It can result in an increase in genetic variation.
Which of these sentences most accurately describes heterochromatin?
It consists mainly of DNA that is more densely packed and that is actively being repressed.
Both dragonflies and pigeons have wings. What insight can this fact give us about evolution?
It demonstrates that evolution can give rise to traits that perform similar functions multiple, independent times
Why is carbon capable of forming single and double bonds?
It has four valence electrons.It has four valence electrons.
How does the modern system of biological classification differ from that of Linnaeus?
It is based on evolutionary relationships
Which of these is a characteristic of a good hypothesis?
It is based on previous observations or results.
What happens to excess energy in the electron transport chain that is not used to establish an electrochemical gradient of protons?
It is dissipated as heat.
What is the function of clathrin?
It is needed for the formation of vesicles.
Which of the following elements can be classified as a noble gas?
Kr (krypton)
The fossil record provides direct evidence for evolutionary relationships among living organisms and the history of life. So why is it controversial?
Large gaps in the record suggest there is not enough evidence to support descent with modification.
Given that milk has a pH of 6 and lemon juice has a pH of 2, which statement is correct?
Lemon juice is 10,000 times more acidic than milk
What characteristic of lipids accounts for the separation of oil into droplets in salad dressing even after vigorous shaking?
Lipids are hydrophobic.
Which of the following is evidence that supports the endosymbiotic theory?
Mitochondria and chloroplasts contain their own DNA.
Which statement about meiosis and mitosis is true?
Mitosis produces daughter cells with the same number of chromosomes as the parent cell.
How were technological improvements important in development of the chromosomal theory of inheritance?
More powerful microscopes and novel staining techniques allowed researchers to view the processes of mitosis and meiosis.
How did Morgan's work expand on Mendel's principles of inheritance?
Morgan discovered that not all alleles are sorted into gametes independent of all other alleles.
Which of these observations would support the idea that some alleles are linked?
Most people who have freckles also have red hair.
Which of the following population sizes (N) of bison would be most affected by genetic drift?
N=10
Which compound is oxidized during fermentation?
NADH
Which molecules transport electrons from the citric acid cycle to the electron transport chain?
NADH and FADH 2
Explain how crossing over increases genetic variation.
Non-sister chromatids from homologous chromosomes exchange genetic information, usually at two or more locations per chromosome depending on the size.
Evolution is considered the core theme of biology. Which of the following would NOT be considered a valid argument for why this is so?
Natural selection is the only explanation for the diversity of life.
What would have to happen in order for a polar covalent bond to form?
One atom would have to share electrons unequally with another atom.
What was unusual about Morgan's results when he crossed two red-eyed flies heterozygous for the trait of white eyes?
Only the males had white eyes.
Why is the relative abundance of carbon in organisms greater than its relative abundance in Earth's crust?
Organisms sequester specific elements to maintain life's processes.
What is the primary difference between the P680 and P700 pairs of molecules?
P680 and P700 differ in the optimal wavelength of light absorbed by each pair of molecules.
In most female mammals, one X chromosome is active and one is inactive in each adult cell. What determines which chromosome is the active one?
Researchers do not know yet.
Which of the following is a reasonable explanation for why regular rice does not contain beta-carotene?
Rice grains are seeds, which do not engage in photosynthesis and do not need pigments.
What did the results of the frog cloning experiments of John Gurdon and his fellow researchers show?
The nucleus of a differentiated cell contains the instructions to direct the development of an organism
What happens when protein kinase A (PKA) phosphorylates phosphorylase kinase in the epinephrine signal transduction pathway?
Phosphorylase kinase becomes activated, and glucose production is enhanced.
Mutation of which of these sequences would have no effect on the initiation of transcription?
Polyadenylation signal
Which of these disorders is not a result of aneuploidy?
Prader-Willi syndrome
Which technique can be used to knock down gene expression?
RNA interference
Which of the following does NOT occur during transcription in bacteria?
RNA splicing
RT-PCR and in situ hybridization are both methods used to detect expression of a single gene. How do the circumstances of their use differ?
RT-PCR is a method of quantifying gene expression, while in situ hybridization is largely useful for localizing where a gene is expressed
What is one way that the replication of eukaryotic DNA generally differs from the replication of prokaryotic DNA?
Replication shortens the lagging strand in eukaryotic DNA.
Penguins in Antarctica are superb swimmers, but they walk awkwardly and cannot fly. There is evidence that penguin ancestors could fly long ago. How might natural selection explain this?
Shorter wings may have helped ancestral penguins survive in their environment by enabling them to swim better, and so genes for shorter wings became common.
How does solubility affect signaling molecules?
Solubility determines where a signaling molecule will bind.
Which step(s) occur in the apoptosis of both plant and animal cells?
The DNA is hydrolyzed by DNAses.
Suppose that a G protein is no longer able to hydrolyze GTP. What effect on the signaling pathway might you predict?
The activity of the pathway might become inappropriately high.
If a plant root cell was not totipotent, what would happen if scientists attempted to clone it?
The cell would only give rise to root cells, not the entire plant.
If a Cdk-cyclin complex becomes more abundant in G2 phase and disappears before G1, what does that suggest?
The complex helps the cell move past the G2 checkpoint.
How does the single genetic defect cause the phenotypes seen in cystic fibrosis?
The defective protein coded by the gene cannot transport molecules across the cell membrane.
In the process of DNA sequencing, a polymerase building a nucleotide sequence from the DNA template will become unable to add more nucleotides when it encounters a dideoxynucleotide. What prevents the polymerase from continuing?
The dideoxynucleotide lacks a hydroxyl group at the 3′ carbon.
Marfan syndrome is associated with tall height and a high risk of heart and eye problems. How does mutation of one gene cause all these symptoms?
The gene codes for a connective tissue protein used in many parts of the body.
What happens in overdominance?
The hybrid has a more extreme phenotype than either parent.
How is eukaryotic pre-mRNA processed prior to creating mature mRNA?
The introns are spliced out, and the exons are combined to form the mature mRNA.
What happens to water molecules as the temperature of water drops below 4°C but before it reaches 0°C?
The kinetic energy of water molecules decreases, and the breaking and re-forming of hydrogen bonds slows down.
Explain how anaphase I might occur in a male rabbit's spermatocytes.
The microtubules connecting to each kinetochore begin to shorten, and the chromosomes are pulled away from the metaphase plate toward opposite poles.
What would happen if a lysosome fused with a mitochondrion?
The mitochondrion would be digested.
Which of these statements is a consequence of the oxygen atom in a water molecule being more electronegative than the hydrogen atoms in that water molecule?
The oxygen atom attracts electrons more strongly than the hydrogen atoms.
Why is deletion of p53 genes damaging to an organism?
The p53 protein pauses the cell cycle for repairs when necessary.
Why do enzymes work poorly at suboptimal pH levels
The pH of the environment can alter the chemistry of the active site, affecting the non-covalent bonds that stabilize the enzyme-substrate complex.
Why do scientists try to use the same restriction enzyme to excise the target DNA sequence and to cut the plasmid?
The plasmid and the insert will have compatible sticky ends.
How is antibiotic resistance used in selection for bacteria carrying recombinant plasmids?
The presence of an antibiotic resistance gene in the plasmids ensures that only bacteria that have picked up the plasmids can grow on media containing an antibiotic.
When a scientist analyzes gene function using gene knockout techniques, what is the ultimate outcome?
The protein that the gene encodes is not made.
Describe how independent assortment during meiosis increases genetic variation.
The random arrangement of chromosomes during metaphase I creates gametes that are genetically unique from one another.
Which situation is most likely to result in two traits showing a linked inheritance pattern?
Their genes are close together on the same chromosome.
The monosaccharides glucose and galactose have the same molecular formula, C 6H 12O 6? How do their structures differ?
Their hydroxyl groups have different spatial arrangements around the asymmetric carbons.
How are sickle-cell anemia and cystic fibrosis related?
They are both due to mutations in a single gene.
Hershey-Chase experiments with bacteriophages and bacterial cells led to which of the following important conclusions?
The structural parts of bacteriophages are composed primarily of protein, and the genetic material is DNA.
In an experiment, chloroplasts that have had their thylakoids removed were exposed to sunlight, CO2, and water. No hexose sugars were formed. What is the most likely explanation for this result?
The thylakoids contained the photosynthetic machinery.
Which of the following best describes how Watson and Crick's model of the DNA molecule was consistent with the function of DNA replication?
The two strands can separate along the relatively weak hydrogen bonds between the complementary nucleotide
What would be the effect of placing an animal cell in a hypotonic solution?
The water in the solution would move via osmosis into the cell and cause it to lyse.
Identify the structural features found in ATP.
a nitrogenous base, a ribose sugar, and three phosphate groups
You breed a female fruit fly that shows the wild-type phenotype but is heterozygous for two traits with a male expressing mutations in both those traits. After many repetitions of the same cross, half the offspring show the wild-type phenotype, and half show both mutations. What can you conclude about the genes for the two traits?
They are on the same chromosome and probably close together.
How can kinases regulate enzyme activity?
They can add phosphate groups to enzymes, typically activating them.
Which statement regarding facultative anaerobes is true?
They can survive in the presence or absence of oxygen.
Which statement regarding obligate anaerobes is true?
They cannot survive in the presence of oxygen.
What is the primary difference between protons and neutrons?
They differ in their charge.
What happens at the origin of replication?
They needed to ensure that all newly synthesized DNA would contain the same marker.
Why did Meselson and Stahl transfer E. coli from media containing 15N to media containing 14N?
They needed to ensure that all newly synthesized DNA would contain the same marker.
What evolutionary advantage do cacti possess?
They store large amounts of water.
Which of the following is the best tool for detecting aneuploidy?
Which of the following is the best tool for detecting aneuploidy?
Would identical twins be expected to have very similar patterns of short tandem repeats (STRs)? Why or why not?
Yes. Because barring any recombination after conception, their repeats will reflect their identical inheritance from the first zygotic division.
Genetic drift can lead to populations with reduced genetic variation. What is one evolutionary consequence of reduced genetic variation?
a decrease in the potential for adaptation to changing environments
What type of genetic cross can demonstrate both the principles of segregation and independent assortment?
a dihybrid cross
Which of the following would NOT be expected as a result of a point mutation?
a duplicated chromosome
What is the "Philadelphia chromosome"?
a modified chromosome 22, produced as a result of chromosome translocation
Complete the following sentence: The resolution of a microscope is defined as its...
ability to distinguish between two adjacent points.
Which molecule enters the citric acid cycle?
acetyl-CoA
Which event in a transduction pathway will most likely result in an increase in concentration of a target protein in the cell?
activating a transcription activator
Which of the following does a catalyst change during a chemical reaction?
activation energy
What molecule do receptor tyrosine kinases use for activation?
adenosine triphosphate
Complete the following sentence: Capillary action, or movement of water up a thin tube, is due to...
adhesion and cohesion.
In fruit flies, brown body color ( B) is dominant to black body color ( b). A brown fruit fly is crossed with a black fruit fly. Both flies are purebred. What will the offspring's genotypes be?
all Bb
Complete the following sentence: The monomers that make up a protein are called...
amino acids
An alternative form of a gene that occurs in the same place on a homologous chromosome (i.e., chromosome pairs of approximately the same length with the same characteristics but each is inherited from a different parent) is ___.
an allele
Phosphorus (P) often occurs as a waxy solid in its natural state. If you subdivide a piece of phosphorus until you have the smallest conceivable amount, do you end up with an atom or an element?
an atom
What class of molecules primarily facilitates the passive movement of water across the cell membrane?
aquaporins
A human syndrome is associated with a deletion of several hundred base pairs on chromosome 17. Which of these visualization techniques would you suggest would be best to see if the deletion were present?
fluorescence in situ hybridization (FISH)
Imagine that you are hiking up a mountain and you notice that the trees are gradually becoming larger as you walk. You hypothesize that large size is an adaptation to colder habitats. Which of the following would NOT be informative in supporting or rejecting this hypothesis?
measuring as many trees as possible along the mountain and plotting a graph of the relationship between temperature and tree size
Why is the nucleus removed from an egg cell to clone an animal?
because it is replaced with the genetic material from a somatic cell nucleus
Why do scientists who explore evolutionary relationships often study ribosomal genes?
because they code for universal features of all organisms
Which of these is the correct order to construct a karyotype?
block cells during mitosis, stain cells, photograph, match up chromosome pairs
Complete the following sentence: Methylation of DNA...
blocks sites for transcription factors.
What is the role of many fungi in the cycling of carbon in an ecosystem?
breaking down and recycling organic molecules from dead organisms and waste
How might a scientific theory be modified?
by the uncovering of new information
One of the differences between RNA and DNA is the nucleotides each contains. What nucleotide does RNA have that DNA does not?
uracil
Which element is present in all organic compounds?
carbon
In the process of alcoholic fermentation, what causes the liquid to bubble?
carbon dioxide
Which of the following molecules can diffuse most easily through a phospholipid bilayer?
carbon dioxide
What process moves carbon from living organisms to the atmosphere?
cellular respiration
Complete the following sentence: Mutation can be described as...
changes in the genomic sequence.
In which of these locations can photosynthesis takes place?
chloroplast
Which of the following contribute most directly to atherosclerosis?
cholesterol and trans fats
Complete the following sentence: Sister chromatids are bound to each other via protein complexes called...
cohesins
Complete the following sentence: Cellular response to insulin signaling demonstrates that...
complex signaling networks can generate a wide variety of cellular responses.
Which of the following types of bonds are NOT commonly used to stabilize an enzyme-substrate complex
covalent bonds
What type of chemical bond is found in the methane molecule?
covalent single bond
You are observing diseased cells in a medical laboratory. You see a cell that contains many food vacuoles, yet is dying from starvation. Which organelle is most likely to be malfunctioning within this cell?
lysosomes
Specialized chlorophyll a molecules responsible for donating electrons to the primary electron acceptor are found in which part of the photosystem?
reaction-center complex
Which of the following is/are an example of an intrinsic trigger for apoptosis?
damaged DNA and mitochondrial damage only
Which term describes the data that are collected during an experiment?
dependent variable
Which of the following scenarios would most likely involve apoptosis?
destruction of muscle cells in the muscles (formerly used to move a caterpillar's body) during its metamorphosis to a butterfly
Which of the following could be measured to construct a photosynthetic action spectrum?
either O 2 production or CO 2 consumption
Which of the following is a source for human stem cells?
embryos and adult somatic cells
Which of the following types of cell signals depends on the circulatory system?
endocrine
What type of inheritance pattern is suggested when the offspring of a dihybrid cross (such as BbCc × BbCc) have a 9:3:4 phenotypic ratio?
epistasis
Which of these inheritance patterns involves interaction of more than one gene?
epistasis
Which of the following is the first step of photosynthesis?
excitation of chlorophyll molecules
Name a human trait that is no longer considered a classic Mendelian trait.
eye color
Which class of food molecules contains the most energy per gram?
fats
Which type of reactions control the energy release from glucose during the citric acid cycle?
redox reactions
Which of the following types of mutations is NOT caused by a point mutation?
frameshift mutation
What term is used to describe all the alleles at every locus for all individuals within a population?
gene pool
A forest fire kills 75% of a shrub population and 100% of the tall trees in an old-growth forest. After some time, the shrubs are much taller than those of a nearby population that was not affected by the fire. What evolutionary mechanism(s) could explain this difference?
genetic drift and/or directional selection
A(n) ___ may be homozygous or heterozygous, whereas a(n) ___ may be described as dominant or recessive.
genotype, phenotype
Which of the following carbohydrates is a primary metabolic fuel for humans?
glucose
Which of the following processes occurs in the cytosol?
glycolysis
After the binding of the G protein-coupled receptor ligand, what molecule does the G protein use for activation?
guanosine triphosphate
Albinism is an autosomal recessive trait. An albino mother has an albino daughter by a healthy man. They plan on having several more children. On average, what proportion of the children are expected to be albino?
half of the sons and daughters
Students compared their resting heart rate to their heart rate after exercise. They measured their resting heart rate after sitting for five minutes; they then did 50 jumping jacks and afterward measured their heart rate. What was the dependent variable of this study?
heart rate
In constructing an expression vector, what characteristic of the promoter is important?
highly active in the bacteria
What influenced Darwin's ideas about the evolution of species during his journey on the surveying mission of the HMS Beagle?
his experience following a major earthquake in Chile
DNA is a double-stranded molecule that commonly must be 'unzipped' into its two constituent strands. Which bond would most likely exist between the DNA strands that would allow them to be easily separated?
hydrogen bonds
The nuclear membrane breaks apart.
in chromatin fibers
Which of the following is NOT a mechanism by which enzymes can lower activation energy barriers?
increasing the kinetic energy of the substrate
An apoptotic signal arising from within the cell is an example of one that will activate the ___ pathway.
intrinsic
Complete the following sentence: After a eukaryotic mRNA strand...
is synthesized in the nucleus using DNA as the template, the mRNA migrates to the cytoplasm, where ribosomes use mRNA as a template to direct the synthesis of proteins.
Which of the following substances would likely increase the acidity of a solution?
lemon juice
Complete the following sentence: The hydrolysis of one mole of ATP can be used to drive reactions that have a ΔG that is...
less than 7.3 kcal/mol.
Suppose a receptor tyrosine kinase is missing the tyrosine residues that are normally phosphorylated. Which of these events would still be predicted to occur normally?
ligand binding
Which of the following terms refers to the photosynthetic reactions that produce ATP and NADPH?
light-dependent reactions
Which kind of reaction converts NAD + to NADH?
reduction
Complete the following sentence: Rapidly growing cells would be performing...
more exocytosis than endocytosis.
Which type of protein removes erroneous segments of DNA after DNA replication is complete?
nucleases
Which of the following is the smallest complete repeating unit of a DNA molecule?
nucleotide
The evolution of aerobic life occurred after an increase in which of the following?
oxygen
What is the ultimate electron acceptor in aerobic cellular respiration?
oxygen
Which atom below is the most electronegative?
oxygen
In a C 4 plant, what is the first molecule that carbon dioxide reacts with?
phosphoenolpyruvate
Which reaction does a kinase catalyze in a signal transduction pathway?
phosphorylation of a target protein
Which of the following is NOT a stage of the Calvin cycle?
photorespiration
Complete the following sentence: Cellular respiration is carried out by...
phototrophs, heterotrophs and producers.
Which of the following structures is used to transfer plasmids between bacteria?
pili
What enzyme is activated by increased cAMP levels in the cell?
protein kinase A
Which is an anabolic process?
protein synthesis
What kind of nucleotide base has a two-ring structure with an amine functional group?
purine
What type of reproductive behavior is required to maintain Hardy-Weinberg equilibrium?
random mating
Which of the following is NOT a process that may provide an adaptive advantage to eukaryotic chromosomes?
rapid cell division
What are the immediate reactant(s) and product(s) in the reaction catalyzed by RuBisCO?
reactants: RuBP, CO2; product: unstable 6-carbon intermediate
Complete the following sentence: In human males, the cells that undergo meiosis are the...
spermatocytes
Which process provides electrons to P680+ in photosystem II to begin linear electron flow in photosynthesis?
splitting of water molecules into electrons, protons and oxygen atoms
Which of the following is the correct sequence for alternation of generations in a fern?
sporophyte → spores → gametophyte → gametes → zygote
Which polysaccharides provide energy storage for plants and animals, respectively?
starch and glycogen
Which of the following is a correct pairing of a polysaccharide and the monosaccharide from which it is made?
starch, glucose
Where does carbon fixation takes place?
stroma
What is the primary source of most of the energy for organisms living on Earth?
sunlight
What does ΔG of a metabolic reaction measure?
the net change in free energy during a reaction
A new polymerase was discovered in a bacterial species that lives in deep-sea vents. It exhibits the ability to add DNA nucleotides to a preexisting DNA daughter strand and to correctly pair nucleotides, and even proofread and replace an incorrect nucleotide it had just placed. Which polymerase does its activity most closely mimic?
the new polymerase resembles DNA polymerase III.
What is the difference between pinocytosis and phagocytosis?
the size of the molecule being ingested
Which definition best describes a cell's metabolism?
the sum of all the chemical reactions occurring in an organism
Which statement best explains the reason for the bent shape of the water molecule?
the tetrahedral arrangement of the two bonding pairs and the two lone pairs of electrons around the oxygen atom
Which process in oxidative phosphorylation releases energy?
the transfer of electrons in redox reactions
Complete the following sentence: The sodium-potassium pump transports...
three sodium ions from the interior to the exterior of the cell and two potassium ions from the exterior to the interior.
The dominant traits in Mendel's pea plants were green pea pods ( G) and round peas ( R). Yellow pea pods ( g) and wrinkled peas ( r) were recessive. If you bred plants heterozygous for both characters, GgRr, with each other, how many more plants with green pea pods and round peas would result, on average, than plants with yellow pea pods and round peas?
three times as many
During carbon fixation, the cell uses NADPH to reduce 1,3-bisphosphoglycerate to form G3P. What is the purpose of this reaction?
to incorporate high-energy electrons into sugars
What is the basic function of the various types of kinases active in the cell cycle control system?
to phosphorylate proteins
Why do carbon-fixation reactions require ATP?
to provide energy for endergonic reactions
The sodium-potassium pump is an active transport pump that uses energy to pump potassium into cells and sodium out of cells. Why is ATP energy required?
to pump the Na + and K + ions against their diffusion gradient
What is the purpose of DNA ligase in gene cloning?
to seal a plasmid after recombination
If a piece of DNA breaks off a chromosome and attaches itself to a non-homologous chromosome at another location, what type of change has occurred?
translocation
What is the role of cAMP in a signal transduction pathway?
transmitting a signal from G proteins to the beginning of the phosphorylation cascade
What is the force that pushes a plant cell membrane against the cell wall?
turgor pressure
In screening for bacterial colonies containing recombinant plasmids, which color indicates that the recombinant plasmid is present?
white
ATP is not the only molecule that can drive reactions. When ATP is depleted during exercise, muscle cells use phosphocreatine to drive the regeneration of ATP. Consider the following half reactions: 1. ATP + H 2O → ADP + P i ΔG = -7.3 kcal/mol 2. Phosphocreatine + H 2O → creatine + P i ΔG = -10.3 kcal/mol From these two reactions, calculate the Gibbs free energy of the following coupled reaction, catalyzed by creatine kinase: Phosphocreatine + ADP → ATP + creatine ΔG = ? Which is the correct net Gibbs free energy of the reaction?
ΔG = -3 kcal/mol
