AP Bio MC (fall final)
22.Which of the following statements best justifies the claim that the conditions in at least one of the experiments could generate the molecular building blocks essential for life? (A) The carbon dioxide (CO2) gas and water (H2O) vapor in experiment 1 could react spontaneously to produce the phospholipids required by the first life-forms. (B) The nitrogen (N2) gas and ammonia (NH3) gas in experiment 1 could provide the elemental nitrogen required for the formation of amino acids. (C) The sulfur dioxide (SO2) gas in experiment 2 could donate the excited electrons required to drive the process of photosynthesis. (D) The methane (CH4) gas in experiment 2 could act as the electron acceptor required to complete the process of cellular respiration.
(B) The nitrogen (N2) gas and ammonia (NH3) gas in experiment 1 could provide the elemental nitrogen required for the formation of amino acids.
12. Some strains of the bacterium Streptococcus pyogenes secrete poisonous substances called exotoxins. The genes encoding the exotoxins are thought to have originated in bacteriophages, which are viruses that infect bacteria. Which of the following is the most likely mechanism by which the S. pyogenes acquired the ability to produce the exotoxins? (A) Bacteriophages engulfed cellular debris from dead bacteria. (B) Bacteriophages in the environment activated bacterial cell division. (C) Bacteriophage DNA became integrated in the bacterial chromosome. (D) Bacteriophage proteins were absorbed into bacteria cells by endocytosis.
(C) Bacteriophage DNA became integrated in the bacterial chromosome.
19. Which of the following scientific questions is most relevant to the model represented in the figure above? (A) Is ATP required for the transportation of sugars across the outer mitochondrial membrane? (B) Do the types of phospholipids in a membrane affect the rate at which molecules enter a cell by passive diffusion? (C) Which molecular substance is actively transported across the plasma membrane? (D) How does temperature affect the movement of molecules into lysosomes?
(C) Which molecular substance is actively transported across the plasma membrane?
31. A cell is treated with a drug that prevents the formation of new lysosomes. The cell continues to transcribe the genes that code for the hydrolytic enzymes that are normally found in lysosomes and continues to translate the mRNAs for those proteins on membrane-bound ribosomes. The hydrolytic enzymes are most likely to accumulate in which of the following cellular structures? (A) Nucleus (B) Mitochondrion (C) Smooth endoplasmic reticulum (D) Golgi complex
(D) Golgi complex
18. Epinephrine is a protein hormone found in many animals. Epinephrine stimulates a signaling pathway that results in the breakdown of glycogen to glucose in the liver cells. Which of the following describes the initial steps in the process whereby epinephrine stimulates glycogen breakdown? (A) Epinephrine binds to a cell-surface receptor; the activated receptor stimulates production of the second messenger, cAMP. (B) Epinephrine binds to a cell-surface receptor; the activated receptor catalyzes the conversion of glycogen to glucose. (C) Epinephrine diffuses through the plasma membrane; the hormone dimerizes in the cytosol. (D) Epinephrine is taken into the cell by endocytosis; glycogen is converted to glucose in the endocytotic vesicle.
A) Epinephrine binds to a cell-surface receptor; the activated receptor stimulates production of the second messenger, cAMP.
2. Mitochondria are found in most eukaryotic cells and contain their own DNA and ribosomes that are similar to those typical of many prokaryotic cells. Which of the following statements is justified by these observations? (A) The mitochondrion is the only location in which eukaryotic cells can synthesize ATP. (B) An ancestral cell most likely engulfed an aerobic prokaryote in a relationship that proved beneficial for both cells. (C) Mitochondrial membranes provide abundant surface area for reactions because of the infoldings called cristae. (D) The mitochondrion plays a role in respiration, but it also stores the cell's extra mRNA.
B) An ancestral cell most likely engulfed an aerobic prokaryote in a relationship that proved beneficial for both cells.
51. Trysinogen Q
B) capable of splitting and activating additional trypsinogen molecules
28.Based on the information presented, which of the following will also occur in response to steroid signaling? (A) Histone protein synthesis will increase because histones maintain the DNA in an optimal conformation for chromosome assembly. (B) Ribosome production will increase because ribosomes are specific for the mRNA with which they bind during translation. (C) DNA replication will increase as a result of the binding of the hormone-receptor complex to the DNA. (D) Production of a specific mRNA will increase as a result of the binding of the hormone-receptor complex to the DNA.
D) Production of a specific mRNA will increase as a result of the binding of the hormone-receptor complex to the DNA.
11. which of the following correctly illustrates a dipeptide and an amino acid in the optimal position to form a tripeptide?
a
19. which of the following best represents the amount of starch, water, and glucose in the dialysis bag?
a
39. which of the following graphs properly represents the humoral immune response when an individual is exposed to the same antigen more than once?
a
40.which of the following representations best shows a portion of an axon at rest?
a
41. Transmission of an action potential across a synapse involves the release of neurotransmitters by the presynaptic neuron. The arrival of the action potential triggers a rise in the calcium concentration in the synaptic terminal, and the change in concentration triggers a release of neurotransmitters into the synaptic cleft. Which of the following representations of the movement of calcium, sodium, and potassium ions best shows how an action potential is transmitted to the postsynaptic neuron?
a
14. Liver cells manufacture glycoproteins, while adipose cells store fat. Which of the following subcellular structures is likely to be more prominent in liver cells than in adipose cells? a) nucleus b) golgi apparatus c) cytoskeleton d) plasma membrane
b) golgi apparatus
50. Based on the info presented, which of the following genetic changes in an individual without diabetes is most likely to result in a disrupted cellular response to insulin signaling similar to that of an individual with type 2 diabetes? a) a deletion in the gene encoding the insulin receptor that removes only the cytoplasmic domain of the protein b) duplication of the gene encoding a PI-3 kinase that results in the synthesis of a muscle-specific variant of the enzyme in skin cells as well as in muscle cells c) a mutation in the gene encoding IRS-1 that causes the protein to be active in muscle cells even in the absence of insulin signaling d) insertion of a small segment of DNA into the promoter of the Glut4 gene that results in increased synthesis of GLUT4 protiens in muscle cells
a) a deletion in the gene encoding the insulin receptor that removes only the cytoplasmic domain of the protein
52. which of the following statements expresses the proper relationship between osmolarity, ADH release, and urine production a) as tissue osmolarity rises, more ADH is released, causing less water to be urine b) as tissue osmolarity rises, less ADH is released, causing less water be urine c) as tissue osmolarity rises, more ADH is released, causing more water to be urine d) as tissue osmolarity rises, less ADH is released, causing more water be urine
a) as tissue osmolarity rises, more ADH is released, causing less water to be urine
62. (figure similarities between atp synthesis in mitochondria and chloroplasts) The figures can best assist in answering: a) do etc create a gradient...? b)what are the sources of energy.... c) what is the optimal temp at which... d) what is the evolutionary relationship between...
a) do etc create a gradient...?
36. The table below describes the action of two genes involved in the regulation of nervous system development in the nematode C. elegans a) gene A promotes neuron development; gene B promotes programmed cell death in neuronal precursors b) Gene A promotes programmed cell death in neuronal precursors; gene B promotes neuron development c) Gene B must be active before gene A can function d) Gene B must be inactive before gene A can function
a) gene A promotes neuron development; gene B promotes programmed cell death in neuronal precursors
53. Which of the following statements is true regarding the movement of substances across cell membranes? a) ions are unable to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic b)Ions are unable to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged c) water is able to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are charged d) water is unable to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged
a) ions are unable to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic
13. which of the following best supports the statement that mitochondria are decendants of endosymbiotic bacteria-like cells a) mitochondria and bacteria possess similar ribsomes and DNA b.) mitochondria and bacteria posses similar nuclei c) glycolysis occurs in both mitochondria and bacteria d) both mitochondria and bacteria have microtubules e) neither possess chloroplasts
a) mitochondria and bacteria possess similar ribsomes and DNA
10. To refine their model of deep-sea biological communities, the researchers investigated areas of the seafloor that are distant from any active hydrothermal vents. Which of the following is the best interpretation of the observation that some octopus species are only found near active hydrothermal vents? a) octopuses depend indirectly on inorganic compounds in the seawater surrounding the hydrothermal vents b) organisms capable of moving across the seafloor are more difficult to observe than are organisms that are rooted in place c) genetic bottleneck events in isolated areas of the deep ocena adversely affect some octopus populations but not others d) biomass in a typical marine food web is expected ot be greater in higher trophic levels than in lower trophic levels
a) octopuses depend indirectly on inorganic compounds in the seawater surrounding the hydrothermal vents
36. sickle cell anemia results from a point mutation in the HBB gene. The mutation results in the replacement of an amino acid that has a hydrophilic R group with an amino acid that has a hydrophobic R group on the exterior of the hemoglobin protein. SUch a mutation would most likely result in altered a) properties of the molecule... b) DNA structure.. c)fatty acid structure... d) protein secondary structure...
a) properties of the molecule...
46. Freshwater bony fish secrete large volumes of very dilute urine. Many marine bony fish secrete small volumes of concentrated urine. Which of the following best explains the differences in nitrogenous-waste excretion between freshwater and marine bony fish? a) the differences arose during divergence, as fish from a common ancestor faced different selective pressures in environments of different osmolarity b) the differences resulted from the evolution of kidneys in independent evolutionary lineages that were adapted to different environmental conditions c) the differences are accidents of evolutionary divergence and are unrelated to the osmotic differences in freshwater and marine environments d) the differences arise in each generation because of the physiological adjustment of individual fish to fluctuating salt concentrations in the environments in which they live
a) the differences arose during divergence, as fish from a common ancestor faced different selective pressures in environments of different osmolarity
34. pig/flu virus question
a) the new viral strain inherited a mixture of genetic material from both avian influenza virus and human flu virus
10. The student analyzed their data from the investigation and concluded that the estimate of the mean of one treatment group was unreliable. Which of the following identifies the treatment group most likely to have provided an unreliable estimate of the mean, and correctly explains why the estimate appears unreliable? a) treatment group II; it has a lower than expected mean absorbance and the largest SEM b) treatment group III; it has a higher than expected mean absorbance and the largest SEM c) Treatment group IV; it has a higher than expected mean absorbance and the smallest SEM d) Treatment group V; it has a lower than expected mean absorbance and the smallest SEM
a) treatment group II; it has a lower than expected mean absorbance and the largest SEM
8. Researchers are investigating the evolutionary relationships among organisms found near deep sea hydrothermal vents and similar organisms found closer to the ocean surface. Which of the following scientific questions is most relevent to the investigation? a) what are the nucleotide sequences of ribosomal RNA genes that are found in the genomes of the different species? b) what large-scale geological events have occurred recently in the Mid-Atlantic ocean? c) Does water temperature at different ocean depths affect the relative levels of dissolved oxygen? d) do species found near deep-sea hydrothermal vents all have the same haploid number of chromosomes?
a) what are the nucleotide sequences of ribosomal RNA genes that are found in the genomes of the different species?
14. salinity of small inland lake Question
b
19. which of the following pairs of functional groups characterizes the structure of an amino acid?
b
3. termites Q
b
36. The healthy human immune system responds... which of the following models depicts a nonspecific response?
b
9. The illustration above is a model of a typical beet root cell. Based on the experimental results, which of the following best represents the effect of acetone on the permeability of cellular membranes?
b) (the one with dashed lines)
38. G3P
b) 14C labeled CO2, because atmospheric carbon is fixed to carbohydrates by photosynthesis
11. Based on the data from the investigation, which of the following is the best scientific question about organisms living in water that is polluted with organic solvents
b) Will organisms living in polluted environments exhibit detrimental effects from an increased permeability of their cellular membranes?
31. the endocrine system incorporates feedback mechanisms that maintain homeostasis. Which of the following demonstrates negative feedback by the endocrine system? a) during labor... b) after a meal... c) at high elevation... d) a transcription...
b) after a meal...
16. which of the following best explains the role of apoptosis in remodeling of the forelimb? a) apoptosis replaces old cells with new ones b) apoptosis involves the regulated activation of proteins in specific cells of the developing forelimb that leads to death of those cells c) apoptosis involves the destruction of extra cells in the... d) apoptosis in the developing forelimb triggers...
b) apoptosis involves the regulated activation of proteins in specific cells of the developing forelimb that leads to death of those cells
In animals, a decrease in body temperature results in which of the following responses? a) release of thyroxine decreases the rate of metabolism b) blood vessels close to the surface of the s constrict c) increased secretion of epinephrine restricts the amount of sugar released into the circulatory system d) the adrenyl glands increase the release of acetlycholine into the circulatory system e) blood vessels in deep muscles constrict so that heat is conserved
b) blood vessels close to the surface of the s constrict
1. a dog is following scent of jackrabbit. Which of the following inaccurately describes how the dogs brain integrates information for smell? a) chemoreceptots in the brain send impulses for smell in the nasal cavity b) chemoreceptor cells in the nasal cavity send impulses to the appropriate area of the brain c) chemoreceptors on epithelial cells of the tongue send hormones to appropriate area of brain d) receptors originating in nose send action potentials to the motor regions of the brain
b) chemoreceptor cells in the nasal cavity send impulses to the appropriate area of the brain
17. Which of the following best supports the claim that organisms of different domains share a common ancestor? a) photsynthesis occurs in chloroplasts, and the citric acid cycle occurs in mitochondria b) glycolysis occurs in both prokaryotic cell and eukaryotic cells c) introns are present in eukaryotic DNA but not in prokaryotic DNA d) errors in DNA synthesis provide some of the genetic variation in a population
b) glycolysis occurs in both prokaryotic cell and eukaryotic cells
61. which of the following is the best prediction of the algal growth if nitrate is added instead of phosphate?
c
26. An answer to which of the following questions would provide the most info about the association between the CFTR mutation and the viscous mucus? a) is the mucus also secreted from the cells... b) how does the disrupted chloride movement affect the movement of sodium ions... c) how does the mutation alter the structure of the CFTR proteins. d) what is the change in nucleotide sequence that results in the cftr mutation?
b) how does the disrupted chloride movement affect the movement of sodium ions...
26.The brain coordinates the circulatory and respiratory system of the human body....... which of the following best describes the physiological response to an overall increase in cellular respiration in the body?
b) in response to low blood pH, the pH sensors send a signal to the brain, which then sends a signal to the diaphragm, resulting in an increased
26. the TROP operon question a) in the absence of tryptophan, the repressor is active and binds to the Trp operator, preventing RNA polymerase from transcribing the operon b) in the presence of tryptophan, the repressor is active and binds to the Trp operator, preventing RNA polymerase from transcribing the operon c) in the absence of tryptophan, the trpR gene is inactive, preventing the production of the repressor that blocks expression of the operon. d) in the presence of tryptophan, the trpR gene is inactive, preventing the production of the repressor that blocks expression of the operon
b) in the presence of tryptophan, the repressor is active and binds to the Trp operator, preventing RNA polymerase from transcribing the operon
the function of which of the following organelles directly requires oxygen? a) ribosome b) mitochondrion c) nucleus d) centriole e) golgi apparatus
b) mitochondrion
41. during respiration, most ATP is formed as a direct result of the net movement of a) potassium against a concentration gradient b) protons down a concentration gradient c) electrons against a concentration gradient d) electrons through a channel e) sodium ions into the cell
b) protons down a concentration gradient
25. the transmission of information from sensory neurons to interneurons typically involves the a) exchange of electrons between specialized proteins embedded in the plasma membrane of the sensory neuron to the plasma membrane of the interneuron b) release of chemical messengers into the space between the axon of the sensory neuron and the plasma membrane of the interneuron c) transfer of a phosphate group from ATP in the sensory neuron to a protein substrate in the interneuron d) flow of protons down an electrochemical gradient through a gated channel between the sensory neuron and the interneuron
b) release of chemical messengers into the space between the axon of the sensory neuron and the plasma membrane of the interneuron
47. malaria and plasmodium question
b) some of the mutations that occur most frequently in samples from patients treated with anitmalarial drugs are detectable in plasmodium samples collected prior to use of animalarial drugs
35. diet question w table a) the diets were too similar, since cellulose and starch are both carbohydrates obtained from eating plants b) the abundance of one of the bacterial species increased in response to the change in diet. c) the change in the diversity of microorganisms had no observable effect on cattle physiology d) the ability of rumen fluid to resist changes in pH conteracted the changes in microorganism diversity
b) the abundance of one of the bacterial species increased in response to the change in diet.
5. which of the following organelles modifies and packages for secretion the materials produced by the ribosomes? a) the chloroplast b) the golgi apparatus c) the nucleus d) the nucleolus e) the mitochondrion
b) the golgi apparatus
all of the following statements about neurotransmitters are generally true except a) may cause hyper or depolarization of the postsynaptic membrane b) they are actively transported across the synaptic cleft c) released from vesicles d) may be enzymatically degraded at the postsynaptic membrane e) bind to specific receptors on the postsynaptic membrane
b) they are actively transported across the synaptic cleft
23. the figure below illustrates a eukaryotic cell. Which of the following best describes how the three structures indicated by the arrows work together? a) to synthesize lipids and modify toxic substances in order to render them harmless b) to synthesize and isolate proteins for secretion or for use in the cell c) to catabolize nutrients and produce ATP for intracellular energy storage d) to synthesize all ribosomal proteins
b) to synthesize and isolate proteins for secretion or for use in the cell
35. In the "RNA world" model for the origin of life, the first protocells (probionts) relied on RNA, not DNA, for information storage and transmission. Which of the following could best be considered evidence in support of the RNA world model? a) DNA is more stable than RNA b)Some RNA molecules in contemporary cells have catalytic function c) RNA is so complex in both structure and function that it must have preceded DNA d) RNA has secondary structure whereas DNA does not.
b)Some RNA molecules in contemporary cells have catalytic function
14. pathogenic bacterium has been engulfed by a phagocytic cell as part of the nonspecific (innate) immune response. Which of the following best illustrates?
c
48. The graph above shows changes in glucaogon and insulin secretions at different concentrations of blood glucose. Which of the following feedback mechanisms is best supported by the data?
c
5. which of the following statements best supports the claim that organisms share fundamental processes as a result of evolution?
c
49. Based on the experimental results, which of the following describes the most likely defect in muscle cells of patients with type 2 diabetes? a) insulin receptor proteins do not reach the cell surface b) insulin does not activate its receptor c) IRS-1 activation is reduced at high insulin concentrations d) GLUT4 blocks glucose from entering cells
c) IRS-1 activation is reduced at high insulin concentrations
4. Which of the following describes a metabolic consequence of a shortage of oxygen in muscle cells? a) an increase in blood pH due to the accumulation of lactic acid b) no ATP production due to the absence of substrate-level phosphorylation c) a buildup of lactic acid in the muscle tissue due to fermentation d) a decrease in the oxidation of fatty acids due to a shortage of ATP
c) a buildup of lactic acid in the muscle tissue due to fermentation
63. which of the following cells would most likely have the greatest concentration of densely packed ER a) an amoeba engulfing small ciliates b) a bioluminescent bacterial cell c) a pancreatic cell engages in the production of digestive enzymes d) a functional phloem cell at maturity e) an epithelial cell whose DNA is replicating before mitosis
c) a pancreatic cell engages in the production of digestive enzymes
45. The figure above shows a series of microscope images taken over time of ovalbumin production in chick oviduct cells in response to stimulation with estrogen. The ovalbumin protein was detected using a fluorescent dye as shown by the white areas in the time-laspse sequence. The microscope images indicate that ovalbumin a) is synthesized on soluble ribosomes and packaged into lysosomes, from which it is secreted into the oviduct b) is synthesized on ribosomes bound to the rough endoplasmic reticulum, and then secreted directly into the oviduct c) crosses the endoplasmic reticulum membrane as it is translated, then moves to the Golgi apparatus, then to vesicles from which it is secreted d) crosses the Golgi apparatus membrane post-translationally, is taken up by the Golgi apparatus and endoplasmic reticulum, then is packaged into secretory vesicles
c) crosses the endoplasmic reticulum membrane as it is translated, then moves to the Golgi apparatus, then to vesicles from which it is secreted
which of the following is responsible for the cohesive properties of water? a) hydrogen bonds between the oxygen atoms of two adjacent water molecules b) covalent bonds between the hydrogen atoms of two adjacent water molecules c) hydrogen bonds between the oxygen atom of one molecule and hydrogen of the other d) covalent between oxygen of one and hydrogen of the other e) hydrogen between water and other molecules
c) hydrogen bonds between the oxygen atom of one molecule and hydrogen of the other
1. which best summarizes an advantage of eukaryotic cells having internal membranes? a) eukaryotic cells are able to reproduce faster because of the presence of organelles b) some organelles, such as mitochondria and chloroplasts, are similar to prokaryotic cells in structure c) organelles isolate specific reactions increasing metabolic efficiency d) compartmentalization leads to a higher mutation rate in DNA, which leads to more new species
c) organelles isolate specific reactions increasing metabolic efficiency
2.) The results of Miller's experiments best support which of the following hypotheses?
c) presumed early atmospheric conditions-- amino acids were required for early life
13. the two sequences for two short fragments of DNA are shown above. Which of the following is one way in which these two segments would differ? a) segment 1 would not code for mRNA because both strands have T, a base not found in RNA b) Segment 1 would be more soluble in water than segment 2 because it has more phosphate groups c) segment 1 would become denatured at a lower temp than 2 bc at base pairs have 2 h bonds d) segment 1 must be from a prokaryote because it has predominantly A-T base pairs
c) segment 1 would become denatured at a lower temp than 2 bc at base pairs have 2 h bonds
2. cell communication is critical for the function of both unicellular and multicellular eukaryotes. Which of the following is likely true of cell signaling? a)cell signaling uses the highest molecular weight molecules found in living cells. b) cell signaling has largely been replaced by other cell functions in higher mammals. c) similar cell signaling pathways in diverse eukaryotes are evidence of conserved evolutionary processes. d) cell signaling functions mainly during early developmental stages
c) similar cell signaling pathways in diverse eukaryotes are evidence of conserved evolutionary processes.
48. INSULIN q: which of the following is a valid interpretation of the experimental results that explains how individuals with type 2 diabetes differ from individuals without diabetes? a)the relatively low levels of glucose uptake in individuals with type 2 diabetes indicate that mobilization of GLUT4 to the cell surface is reduced in muscle cells of those individuals. b)the relatively low levels of glucose uptake in individuals with type 2 diabetes indicate that no functional GLUT4 protein is produced in the muscle cells of those individuals c) the absence of activated insulin receptors in individuals with type 2 diabetes indicates that no insulin is secreted by the pancreatic cells of those individuals d) the absence of activate IRS-1 in individuals with type 2 diabetes indicates that no functional insulin receptor protein is produced in the muscle cells of those individuals
c) the absence of activated insulin receptors in individuals with type 2 diabetes indicates that no insulin is secreted by the pancreatic cells of those individuals
38. based on the diagram which of the following most likely contributes to the specific pattern of geneX a) expression of gene x produces large... b)the general transcription factors inhibit... c) the activator is a sequence specific... d) the enhancer is a unique DNA...
c) the activator is a sequence specific...
15. intravenous solutions administered to patients are normally isotonic. Which of the following is most likely if an IV of distilled water is administered to a patient? a) the cells that are exposed to hypotonic solutions will shrink as a result of salt moving into the blood b) the liver will secrete additional bile salts into the blood to raise the tonicity of the administered fluid c) the cells that are exposed to hypotonic solutions will expand as water moves osmotically into the cells from the blood d) the patient's respiration rate will slow to compensate for the higher levels of circulating blood
c) the cells that are exposed to hypotonic solutions will expand as water moves osmotically into the cells from the blood
63. Hedgehog question a) treating patients with a molecule that is structurally similar to Hedgehog... b)Injecting patients with embryonic cells so that.. c) treating patients with a membrane soluble... d) injecting patients with a prep of purified...
c) treating patients with a membrane soluble...
23. sample of human blood=placed in test tube. which is the most probable outcome? a) view 1 bc RBC membranes are freely permeable to water b) view 2 bc the RBCs use energy to allow sodium entry and to pump water out c) view 2 bc the rate of water movement into the RBCs equals the rate of water movement out of the cells d) view 3 bc
c) view 2 bc the rate of water movement into the RBCs equals the rate of water movement out of the cells
which of the following best describes why the polymerase chain reaction is a standard technique used in molecular biology research?
c)it can produce large amounts of specific DNA sequences
16. lactose digestion in E coli, which figure?
d
46. Which of the following diagrams correctly identifies both the structure of the neurons and the direction of information flow between neurons?
d
6. when DNA replicates...replication fork
d
34.Which of the following best explains the ability of MRSA to evade existing drug therapies? a) MRSA have very long generation times and very large population sizes b) MRSA develop new alleleles by intentionally introducing specific mutations that will give them a selective advantage over other bacteria. c)MRSA metabolize many drugs in their lysosomes and therefore evolve resistance at a high rate d) MRSA exchange genetic material with other antibiotic-resistant bacteria, which can spread resistance in the S. aureus population
d) MRSA exchange genetic material with other antibiotic-resistant bacteria, which can spread resistance in the S. aureus population
39. following the surgical removal of thyroid gland, the level of TSH in the blood will increase, Which is the best explanation? a) residual will bind to cells signaling more secretion b) Thyroxine will remain bound to receptors... c) Thyroxine that was stored in the anterior pituitary prior... d) a decrease in thyroxine levels means...
d) a decrease in thyroxine levels means...
46. see photo: which of the following is most likely to reduce the binding of the active ligand to its receptor? a) a change in the cytoskeletal attachement of transmembrane proteins b) the presence of a large amount of the precursor form of the ligand c) an increase in the ratio... d) a mutation in the receptor gene...
d) a mutation in the receptor gene...
28. The Stanley miller apparatus demonstrated that organic molecules could assemble spontaneously in an environment lacking free oxygen and containing water, methane, and ammonia in the presence of an abundant energy source, such as electric discharge..... organic soup..... etc etc.... The new data about the composition of the early atmosphere had which of the following effects on origin-of-life hypotheses? a) Miller's work was discarded as not relevant to an origin-of-life hypothesis. b) Miller's work was used to refute the new hypothesis about the composition of the atmosphere c) the organic soup hypothesis was abandoned as no longer being supportable d) a new organic soup hypothesis was proposed to account for the new data about the atmosphere
d) a new organic soup hypothesis was proposed to account for the new data about the atmosphere
35. Which of the following describes the most likely source of genetic variation found in the tryptophan synthesis pathways of both species? a) exchange of genetic info... b)viral transmission of genetic info required to synthesize tryptophan occurs c) random assortment of chromosomes leads to genetic variation d) errors in DNA replication lead to genetic variation
d) errors in DNA replication lead to genetic variation
49. which of the following best describes an advantage that eukaryote organisms have over prokaryote organisms? a) prokaryotes lack a cell membrane and are unable to control what enters or exits the cell b) eukaryotes have a nuclear envelope separating their DNa from the rest of the cell, which increases the likelihood of advantageous mutations. c) eukaryotes have mitochondria and chloroplasts that contain their own genome d) eukaryotes have organelles that allow for compartmentalization of cellular processes, which increases the efficiency of those processes.
d) eukaryotes have organelles that allow for compartmentalization of cellular processes, which increases the efficiency of those processes.
41. long term abuse of AAS would a) stimulate FSH secretion b)stimulate testosterone production c) stimulate LH secretion d) reduce sperm production
d) reduce sperm production
33. When a stimulus is applied to a receptor in the skin, an action potential is propagated along a neuron to the brain, where another signal is sent back to the muscle for a response. which of the following best describes what occurs when the action potential reaches a chemical synapse at the end of an axon? a) the action potential jumps from one axon to the next connecting axon b) the action potential travels through the synapse to the next connecting dendrite c) the action potential jumps the synapse to the next connecting dendrite d) the action potential causes a release of neurotransmitters that travel across the synapse
d) the action potential causes a release of neurotransmitters that travel across the synapse
12. Individuals with PCD often have severe respiratory problems due to defective cilia. Males with PCD are often sterile because they produce sperm with defective flagella. which is most likely the cause: a) the mitochondria are defective and do not produce sufficient protein to synthesize microtubules in the cilia and flagella b)the plasma membrane of the alveoli is not permeable to carbon dioxide during respiration because it is too hydrophobic c) the golgi bodies secrete an enzyme that destroys the proteins in the flagella and cilia d) the cells do not produce functional motor protens in flagella and cilia
d) the cells do not produce functional motor protens in flagella and cilia
27. Thyroxin is a hormone that increases metabolic activities within various tissue targets. Low levels of circulating thyroxin trigger the secretion of thyroid-stimulating hormone (TSH) from the anterior pituitary. TSH secretion then stimulated throxin production and release by the thyroid gland. The increased level of circulating thyroxin inhibits further secretion of TSH from the anterior pituitary Based on the info provided, which of the following can most likely be concluded about the TSH-thyroxin loop? a) A person taking thyroxin to supplement low thyroxin secretion will produce more TSH. b) Increased thyroxin production would cause elevated ribosomal activity in the anterior pituitary c) the structure of the loop would lead to elevated thyroid and tissue activity due to positive feedback d) the feedback mechanism would maintain relatively constant levels of thyroxin throughout tissue targets
d) the feedback mechanism would maintain relatively constant levels of thyroxin throughout tissue targets
27-31 rabbit/ tadpole
d, b, d, c, a
39. All of the following were likely present on the primitive Earth during the evolution of self-replicating molecules EXCEPT: a) amino acids and molecules b) nitrogen c)simple carbs d) freestanding liquid water e) an o2 rich atmosphere
e) an o2 rich atmosphere
Which of the following provides the weakest evidence that mitochondria were once free-living prokaryotes? a) mitochondrial ribosomes resemble those of prokaryotes b) mitochondria have DNA that is circular and does not have associated protein c) enzyme pathways on mitochondrial membranes resemble those found on modern prokaryote membranes d) mitochondria reproduce by a process similar to binary fission e) mitochondria and prokaryotes both are found in a variety of sizes
e) mitochondria and prokaryotes both are found in a variety of sizes
16. the diagram above represents a typical rod-shaped bacterium. Which of the following best describes a feature shown in the diagram that is unique to archaea and bacteria? a) the organism is surrounded by a cell wall b) the organisms contains ribosomes c) the organism does not have a nuclear membrane surrounding its genetic material d) the organism is not capable of making or providing itself with ATP
the organism does not have a nuclear membrane surrounding its genetic material