Biology Final
G protein- adenyl cyclase- cAMP- protein kinase
1. Following activation of a receptor, which sequence below represents the correct order in which components will be involved in a signaling pathway that utilizes the second messenger cAMP?
3
1. The following question refers to the essential steps in meiosis described below. 1. formation of four new nuclei, each with half the chromosomes present in the parental nucleus 2. alignment of homologous chromosomes at the metaphase plate 3. separation of sister chromatids 4. separation of the homologs; no uncoupling of the centromere 5. synapsis; chromosomes moving to the middle of the cell in pairs Which of the steps take(s) place in both mitosis and meiosis?
Small hydrophobic
1. What kinds of molecules pass through a cell membrane most easily?
A plant cell but not an animal cell
A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, chloroplasts, and mitochondria. It could be
20
A cell in G2 of the cell division cycle contains 20 chromatids. How many centromeres are present in this cell?
HT
A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism?
haploid, and the chromosomes are each composed of two chromatids
After telophase I of meiosis, the chromosomal makeup of each daughter cell is
Haploid, and the chromosomes are each composed of a single daughter chromosome
After telophase II of meiosis, the chromosomal makeup of each daughter cell is
A population
All the individuals of a particular species living within the bounds of a specified area are collectively described by which of the following terms?
Allowing the organism to adjust to changes in environmental conditions
Altering patterns of gene expression in prokaryotes would most likely contribute to the organism's survival in which of the following ways?
Presence of a fixed amount of a competitive inhibitor
An enzyme-catalyzed reaction is conducted in a test tube with a fixed amount of enzyme. Increasing the substrate concentration in the test tube may overcome the effect of which of the following conditions?
they consume energy to synthesize polymers from monomers
Anabolic pathways share which of the following characteristics?
After an error occurring in anaphase I or anaphase II
At what point in meiosis is a chromosome lost so that, after fertilization with a normal gamete, the result is an embryo with the chromosomal makeup of 45, X0?
the organism ultimately must obtain all of the necessary energy for life from its environment
Based on the first law of thermodynamics, which of the following statements about a living organism is true?
Positively charged
Based on your knowledge of the polarity of water molecules, the solute molecule depicted in Figure 2.7 is most likely
1/2
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 crosses BbTt × BBtt will be expected to have black fur and long tails?
Accepting H+ from a solution when acids are added.
Buffers are substances that help resist shifts in pH by
Oxidation of pyruvate to acetyl CoA and the citric acid cycle
Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?
Increasing the percentage of unsaturated phospholipids in the membrane
Cell membranes in plants that thrive in extreme cold are able to remain fluid by
Heritable traits that enhance their survival and reproductive success in the local environment
Charles Darwin proposed that "descent with modification" resulted when organisms of a particular species become adapted to their environment because they possess which of the following characteristics?
establishment of a proton gradient across the thylakoid membrane
Chemiosmosis in chloroplasts involves which of the following processes?
the concentration of hydrogen ions in solution X is 1000 times as great as the concentration of hydrogen ions in solution Y
Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that
Hydrogen bonds
Conversion of liquid water to water vapor requires breaking which of the following types of bonds?
binding of a substrate molecule to one active site in a multisubunit enzyme stimulates the binding of substrate molecules to the active sites of other subunits
Cooperativity is a form of allosteric activation in which
Pleiotropy
Cystic fibrosis affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections. Which of the following terms best describes this expression of phenotypes?
DNA polymerase I
During DNA replication in E. coli, which of the following enzymes removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments?
During meiosis I only
During which process does independent assortment of chromosomes occur?
Mitochondrial intermembrane space
Energy released by the electron transport chain is used to pump H+ into which location in eukaryotic cells?
An increase in the entropy of the universe
Energy transformations in organisms are always associated with
Met-ser-ser-leu-ser-leu
Examine the table of codons in the figure above. What amino acid sequence will be produced based on the following mRNA codon sequence? 5'-AUG-UCU-UCG-UUA-UCC-UUG-3'
Rough ER
Extracellular matrix proteins are produced by ribosomes in which part of a eukaryotic cell?
420 nm
Figure 8.1 shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. What wavelength of light is most effective in driving photosynthesis?
siRNA
Gene expression can be blocked by a process called RNA interference. Which of the following molecules is involved in this process?
Protons plus neutrons
Given only a mass number, one can deduce the number of ________ in each atom of an element.
They interfere with viral replication
How do antiviral drugs help to treat viral infections?
by base pairing to sites on both the intron and nearby exons??
How do small RNAs in the spliceosome initiate the splicing of the pre-mRNA?
Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the transfer of electrons from one atom to the other
How does the formation of covalent bonds differ from the formation of ionic bonds between two atoms?
2
How many electron pairs are shared between the two carbon atoms in a molecule that has the formula C2H4?
Proteins will unfold (denature)
How will brief heating (to 95°C) affect macromolecular structures in aqueous solution?
18 chromosomes
If a sexually reproducing organism has a diploid number of 36, how many individual chromosomes would any of its gametes have?
Prophase I
If chiasmata can be seen in a cell under a microscope, which of the following meiotic processes must have occurred?
5'-TGCAAT-3'
If one strand of a DNA molecule has the sequence of bases 5'-ATTGCA-3', the other complementary strand would have the sequence
glycogen
If two of the molecules shown in Figure 3.7 are linked together, carbon-1 of one molecule to carbon-4 of the other, the bond that is formed would be found in which of the following polymers?
The membrane receptor protein undergoes a conformational change
Immediately after a membrane receptor protein binds to its ligand, which of the following processes occurs?
DNA polymerase I
In E. coli, which of the following enzymes removes the RNA primer from the 5' end of the DNA fragment?
3
In Figure 2.4, how many unpaired electrons does phosphorus have in its valence shell?
On the exterior surface of the protein, interacting with water
In a normal cellular protein, where would you expect to find a hydrophilic amino acid such as asparagine?
1 and 4 only
In a particular plant, leaf color is controlled by gene locus D. Plants with at least one D allele have dark green leaves, and plants with the homozygous recessive dd genotype have light green leaves. A true-breeding dark-leaved plant is crossed with a light-leaved one, and the F1 offspring is allowed to self-pollinate. The predicted outcome of the F2 is diagrammed in the Punnett square shown in the figure above, where 1, 2, 3, and 4 represent the genotypes corresponding to each box within the square. Which of the plants will be true-breeding?
Polar covalent bonds
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
A + C = G + T
In an analysis of the nucleotide composition of DNA, which of the following will be found in a given DNA molecule?
It loses electrons and loses potential energy.
In an oxidation-reduction reaction, how is the reducing agent changed?
0
In certain plants, the tall trait is dominant to the short trait. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short?
Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form
In his transformation experiments, which of the following results did Griffith observe?
activation of SRY in male embryos and development of testes
In humans, clear sex differentiation occurs not at fertilization but after the second month of gestation. What is the first event of this differentiation?
Activation energy of the reaction
In most exergonic reactions, before products can be formed, the reactants must first overcome a thermodynamic barrier known as the
Decrease in glucose and increase in cAMP
In positive control of several sugar-metabolism-related operons, the cAMP receptor protein (CRP) binds to DNA to stimulate transcription. Which of the following events activates CRP?
A proton gradient across a membrane
In the complete reactions of aerobic respiration, the energy for most of the ATP produced is provided by
host cell DNA polymerase
In the figure above, at the arrow marked II, what enzyme is being utilized?
The proteins self-assemble
In the figure above, when new viruses are being assembled during the step labeled IV, how is the assembly of the new virus particles completed?
The cells would not respond to growth factors from nearby cells
In what way would the lack of receptors for local paracrine signal molecules affect animal cells?
3' to 5' along the template strand
In which direction does RNA polymerase move along the DNA?
Reductionism
Investigating the molecular structure of DNA in order to understand the chemical basis of inheritance is an example of which approach utilized in the study of biology?
Cells must be attached to a substrate or extracellular matrix of a tissue
Most animal cells exhibit anchorage dependence, which means that in order to divide,
Microtubules and motor proteins
Movement of vesicles within the cell depends on what cellular structures?
Homeotic genes
Mutations in which of the following genes lead to transformations in the identity of entire body parts?
A male inherits only one allele of the X-linked gene controlling hair color
Normally, only female cats have the tortoiseshell phenotype because
Two more neutrons than carbon-12
One difference between carbon-12 ( C) and carbon-14 ( C) is that carbon-14 has
Translocation
One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called?
Gap junctions
Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?
activates motor molecules at the centromere to begin disassembly of spindle microtubules
Progression through the M phase checkpoint is stimulated by a complex that does which of the following things?
Channel proteins
Proteins that allow the diffusion of ions across membranes in the direction of their concentration gradients are most likely
XNXn and XNY
Red-green color blindness is a sex-linked recessive trait in humans. The normal, dominant allele is symbolized with XN, and the recessive allele is symbolized with Xn. Two people with normal color vision have a color-blind son. What are the genotypes of these parents?
I only
Refer to the life cycles illustrated in Figure 10.6 above. Which of the life cycles is (are) typical for animals?
cause a structural change in each phosphorylated protein.
Signal transduction pathways that include a phosphorylation cascade
The cell becoming turgid
Submerging a plant cell in distilled water will result in
Shriveling of the cell
Submerging a red blood cell in a hypertonic solution will result in
Anterior structures would form in both sides of the embryo
The bicoid gene product is normally localized to the anterior end of the embryo. If large amounts of the product were injected into the posterior end as well, which of the following would occur?
cyclins
The cell cycle is regulated at the molecular level by a set of proteins known as
Oxidation of C6H12O6 and reduction of O2
The complete reactions of cellular respiration in the presence of oxygen (C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy) result in which of the following?
pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis is highly selectivity
The difference between pinocytosis and receptor-mediated endocytosis is that
X chromosome inactivation in the embryo is random and produces different patterns in each individual
The first cloned cat, called Carbon Copy, was a calico, but she looked significantly different from her female parent. Why?
A gene from an organism can theoretically be expressed by any other organism
The genetic code is essentially the same for all organisms. Based on this information, one can logically assume which of the following statements to be correct?
A polypeptide missing an amino acid
The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the most likely result of this mutation in the protein product?
transmitting the signal from an activated receptor to the next protein in the pathway.
The primary function of G proteins in signal transduction is
Light energy
The primary source of energy for producers in an ecosystem is
Protein factors and GTP
The process of translation in both prokaryotes and eukaryotes requires tRNAs, amino acids, and ribosomal subunits. Which of the following components must also be present for translation to proceed?
Low [Na+] and high [K+] inside the cell and high [Na+] and low [K+] outside
The sodium-potassium pump generates the following concentration gradients across the plasma membrane:
The water level is higher in side A than in side B.
The solutions in the two arms of the U-tube shown in Figure 5.2 are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half-filled with a solution of 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels are equal. After the system depicted in the figure reaches equilibrium, what changes are observed?
B (two sets of each)
The unlettered circle at the top of the figure above shows a diploid nucleus with four chromosomes that have not yet replicated. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is black, and the other is gray. The circles labeled A-E show various combinations of these chromosomes. What is the correct chromosomal condition for a nucleus at prophase of mitosis?
E (single of 4)
The unlettered circle at the top of the figure above shows a diploid nucleus with four chromosomes that have not yet replicated. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is black, and the other is gray. The circles labeled A-E show various combinations of these chromosomes. Which image displays the chromosomal composition of one daughter nucleus at telophase of mitosis?
Secondary
The α helix and β pleated sheet are examples of which level of protein structure?
-20 kcal/mol
The ∆G for a particular enzyme-catalyzed reaction is -20 kcal/mol. If the amount of enzyme in the reaction is doubled, what will be the ∆G for the new reaction?
The rules for base pairing between the third base of a codon and tRNA are flexible
There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that
Chloroplasts
Thylakoids, DNA, and ribosomes are all components found in
Number of protons plus neutrons
Two atoms that have the same mass number must have the same
Compounds that have polar covalent bonds
Water molecules are able to form hydrogen bonds with
ATP and NADPH
What are the products of linear electron flow?
NADPH
What compound provides the reducing power for the Calvin cycle reactions?
It makes it transcriptionally inactive
What effect does methylation have on DNA?
an RNA with enzymatic activity
What is a ribozyme?
It introduces a premature stop codon into the mRNA
What is the effect of a nucleotide-pair substitution that results in a nonsense mutation in a gene?
It uses viral RNA as a template for DNA synthesis
What is the function of reverse transcriptase in retroviruses?
It binds to the stop codon in the A site in place of a tRNA.
What is the function of the release factor in translation?
Relieving strain in the DNA ahead of the replication fork
What is the function of topoisomerase?
Electron beams have much shorter wavelengths than visible light
What is the primary reason that a modern transmission electron microscope (TEM) can resolve biological structures as small as 2 nm, whereas 200 nm is the limit of resolution for a light microscope?
They are inversely related.
What is the relationship between wavelength of light and the quantity of energy per photon?
redox reactions in the electron transport chain
What is the source of the energy used to generate the proton gradient across the inner mitochondrial membrane?
Nondisjunction in either parent
What is the source of the extra chromosome 21 in an individual with Down syndrome?
One cell with two nuclei, each identical to the nucleus of the parent cell
What will be the result if a eukaryotic cell completes mitosis but does not undergo cytokinesis?
Centrosome
Where do the microtubules of the spindle originate during mitosis in animal cells?
thylakoid membranes of chloroplasts
Where is the electron transport chain associated with photophosphorylation located in plant cells?
Covalent bond
Which bond or interaction would be most difficult to disrupt when compounds are put into water?
Substrate-level phosphorylation
Which chemical process generates the ATP produced in glycolysis?
E
Which drawing in Figure 2.3 is of the electron configuration of a sodium 11Na+ ion?
D (COOH)
Which molecule shown in Figure 3.5 contains a carboxyl group?
B (COH)
Which molecule shown in Figure 3.5 has a carbonyl functional group in the form of an aldehyde?
Hydrolysis of glycogen to release glucose monomers
Which of the descriptions below is an example of an exergonic reaction?
A base-pair deletion
Which of the following DNA mutations is likely to have the most negative effect on the protein it specifies?
Dehydration reactions assemble polymers, and hydrolysis reactions break down polymers.
Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?
The proteins on its surface and that of the host
Which of the following characteristics determine a virus's host range?
The anterior-posterior axis
Which of the following characteristics would a mutation in the bicoid gene in Drosophila most likely effect?
Light->chemical->heat
Which of the following correctly describes the forms by which energy flows through an ecosystem from entry to exit?
2 NADH, 2 pyruvate, and 2 ATP
Which of the following correctly lists all of the energy-containing molecules produced by the catabolism of one molecule of glucose in glycolysis?
Growing one set of 10 seedlings under white light and one set of the same type of seedlings under red light and measuring their growth over a period of two weeks
Which of the following descriptions constitutes a controlled experiment?
The cyclic AMP and lactose levels are both high within the cell.
Which of the following environments would most likely lead to the transcription of the lactose operon?
The small subunit of the ribosome recognizing and attaching to the 5' cap of mRNA
Which of the following events in translation is the first to occur in eukaryotes?
Synapsis of pairs of homologous chromosomes
Which of the following events occurs in meiosis but not in mitosis?
Segmentation genes
Which of the following genes map out the basic subdivisions along the anterior-posterior axis of the Drosophila embryo?
glucose → NADH → electron transport chain → oxygen
Which of the following indicates a primary path by which electrons travel downhill energetically during aerobic respiration?
Hundreds of cultures of a unicellular alga are incubated in the presence of light, and in all of the samples the cells congregate on the side of the culture toward the light. Therefore, the alga is phototactic (attracted to light).
Which of the following is an example of inductive reasoning?
Metabolism consists of all the energy transformation reactions in an organism
Which of the following is the most comprehensive definition of metabolism in living organisms?
RNA polymerase must bind to the promoter, and the repressor must be inactive.
Which of the following must occur in order for a repressible operon to be transcribed?
DNA or RNA
Which of the following nucleic acids make(s) up viral genomes?
same amount of dots on both circles
Which of the following pairs of atoms would be most likely to form a polar covalent bond?
Fusion of an adult cell's nucleus with an enucleated egg, followed by incubation in a surrogate
Which of the following processes can be used to clone animals?
Splitting of water molecules
Which of the following reactions produces the oxygen released by photosynthesis?
Biosphere->ecosystems->communities->populations->organisms
Which of the following represents the correct hierarchy of biological organization from large scale to smaller scale?
The virus enters the cell, host enzymes replicate the viral genome, enzymes transcribe the viral genome into mRNA
Which of the following responses correctly lists the order of events in a generalized viral replicative cycle?
Double-stranded DNA, four kinds of DNA nucleotides, primers, origins of replication
Which of the following sets of materials is required by both eukaryotes and prokaryotes for DNA replication?
The 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY)
Which of the following statements about humans is true?
ATP serves as an energy shuttle in the cell, coupling exergonic and endergonic reactions
Which of the following statements best describes the critical role that ATP plays in cellular metabolism?
It is the recognition site for a specific transcription factor
Which of the following statements best describes the function of the TATA box in eukaryotic promoters?
Bacteria have one type of RNA polymerase, whereas eukaryotes have at least three.
Which of the following statements correctly compares transcription in prokaryotes and eukaryotes?
Protein modification and sorting
Which of the following statements correctly describes a function of the Golgi apparatus?
Electrons released from the P680 chlorophyll are replaced by electrons derived from water.
Which of the following statements correctly describes a reaction associated with photosystem II?
It can allow the production of protein products from a single mRNA
Which of the following statements correctly describes alternative RNA splicing?
In rabbits and many other mammals, one genotype (ee) prevents any fur color from developing
Which of the following statements correctly describes an example of epistasis?
A genome is a complete set of all of an organism's genes.
Which of the following statements correctly describes an organism's genome?
Monosomy X is the only known viable human monosomy
Which of the following statements correctly describes aneuploid conditions?
The leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction
Which of the following statements correctly describes how the leading and the lagging strands of DNA formed during DNA replication differ?
Each nucleosome consists of eight histones.
Which of the following statements correctly describes one characteristic of histones?
Heterochromatin is highly condensed, whereas euchromatin is less compact
Which of the following statements correctly describes one difference between heterochromatin and euchromatin?
The phage genome replicates along with the host genome
Which of the following statements correctly describes the lysogenic cycle of lambda (λ) phage?
The molecule binds to the repressor protein and activates it
Which of the following statements correctly describes the role of a molecule that controls a repressible operon?
DNA methylation reduces transcription, and histone acetylation promotes transcription
Which of the following statements correctly describes the role of histone acetylation and DNA methylation in gene regulation?
They can encode proteins that promote DNA repair or cell-cell adhesion
Which of the following statements correctly describes tumor-suppressor genes?
An experiment with at least two groups, one of which does not receive the experimental treatment
Which of the following statements describes a controlled experiment?
to oxidize NADH to NAD+
Which of the following statements describes a primary function of both alcohol fermentation and lactic acid fermentation?
An organism that dies after five days of life but leaves 10 offspring, all of whom survive to reproduce
Which of the following statements describes an individual that is likely to be the most successful in an evolutionary sense?
Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many
Which of the following statements describes one difference between DNA replication in prokaryotes and DNA replication in eukaryotes?
GTP provides the energy for the formation of the initiation complex, using initiation factors
Which of the following statements describes one of the functions of GTP in translation?
They can give rise to all cell types in the organism
Which of the following statements is true of embryonic stem cells?
Abnormal stimulation of cell growth and division
Which of the following would result from a mutation in a proto-oncogene?
II only
Which of the three types of viruses shown in the figure above would you expect to include glycoproteins as part of their overall structure?
Central vacuole
Which organelle occupies much of the volume of a plant cell?
Anaphase I
Which phase of meiosis is represented in the figure above?
Metaphase II
Which phase of meiosis is represented in the figure above?
The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages
Why are hydrocarbons insoluble in water?
Their carbon skeletons are composed of primarily C-C and C-H bonds.
Why are the vertebrate sex hormones estrogen and testosterone considered to be lipids?
To observe whether or not a recessive trait would reappear
Why did Mendel continue some of his experiments to the F2 generation?
They have exited the cell cycle and entered G0
Why do most cells in the human body divide infrequently?
DNA polymerase can only add nucleotides to the free 3' end
Why does a new DNA strand elongate only in the 5' to 3' direction in replication?
