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The resting membrane potential depends on which of the following?
I. Active transport
II. Selective permeability
III. Differential distribution of ions across the axonal membrane
A. III only
B. I and II only
C. II and III only
D. I, II, and III -Answer D The resting potential depends on active transport (the
Na+K+-ATPase pump) and the selective permeability of the axon membrane to K+ than
to Na+, which leads to a differential distribution of ions across the axonal membrane.
The Krebs cycle in humans occurs in the
A. mitochondrial matrix
B. inner mitochondrial membrane
C. outer mitochondrial membrane
D. intermembrane space -Answer A The Krebs cycle occurs in the mitochondrial
matrix. Don't forget to review the site of each stage of aerobic respiration. Glycolysis,
the first step in aerobic respiration, occurs in the cytoplasm. The electron transport
chain occurs along the inner mitochondrial membrane. Oxidative phosphorylation
occurs as protons (H+ ions) move from the intermembrane space to the mitochondrial
matrix.
A heterotroph
A. obtains its energy from sunlight, harnessed by pigments
B. obtains its energy by oxidizing organic molecules
C. makes organic molecules from CO2
D. obtains its energy by consuming exclusively autotrophs -Answer B A heterotroph
obtains its energy from organic molecules. An autotroph obtains energy from sunlight
utilizing pigments such as chlorophyll, and uses CO2 and water to make organic
,molecules. Therefore, (A) and (C) can be eliminated. Heterotrophs can obtain their
energy from ingesting autotrophs, but they can also consume other heterotrophs.
Regarding meiosis and mitosis, one difference between the two forms of cellular
reproduction is that in meiosis
A. there is one round of cell division, whereas in mitosis there are two rounds of cell
division
B. separation of sister chromatids occurs during the second division, whereas in mitosis
separation of sister chromatids occurs during the first division
C. chromosomes are replicated during interphase, whereas in mitosis chromosomes are
replicated during prophase
D. spindle fibers form during prophase, whereas in mitosis the spindle fibers form during
metaphase -Answer B In meiosis, the sister chromatids separate during the second
metaphase of meiosis (Meiosis II), whereas the sister chromatids separate during
metaphase of mitosis.
A feature of amino acids NOT found in carbohydrates is the presence of
A. carbon atoms
B. oxygen atoms
C. nitrogen atoms
D. hydrogen atoms -Answer C Amino acids are organic molecules that contain
carbon, hydrogen, oxygen, and nitrogen, so eliminate (A), (B), and (D). Don't forget to
associate amino acids with nitrogen because of the amino group (NH2).
Which of the following is NOT a characteristic of bacteria?
A. Circular double-stranded DNA
B. Membrane-bound cellular organelles
C. Plasma membrane consisting of lipids and proteins
D. Ribosomes that synthesize polypeptides -Answer B Unlike eukaryotes,
prokaryotes (which include bacteria) do not contain membrane-bound organelles.
Bacteria contain circular double-stranded DNA, ribosomes, and a cell wall, so (A) and
(D) are incorrect. Also eliminate (C) because bacterial cell membranes are made up of a
bilipid layer with proteins interspersed.
Which of the following best explains why a population is described as the evolutionary
unit?
A. Genetic changes can only occur at the population level.
B. The gene pool in a population remains fixed over time.
C. Natural selection affects individuals, not populations.
D. Individuals cannot evolve, but populations can. -Answer D Populations can be
described as the evolutionary unit because changes in the genetic makeup of
,populations can be measured over time. Eliminate (A), as genetic changes occur only at
the individual level. Only under Hardy-Weinberg equilibrium does the gene pool remain
fixed over time in a population. However, this statement does not explain why the
population is the evolving unit, so (B) is incorrect. Choice (C) is true but does not
address the question.
The endocrine system maintains homeostasis using many feedback mechanisms.
Which of the following is an example of positive feedback?
A. Infant suckling causes a mother's brain to release oxytocin, which in turn stimulates
milk production.
B. An enzyme is allosterically inhibited by the product of the reaction it catalyzes.
C. When ATP is abundant the rate of glycolysis decreases.
D. When blood sugar levels decrease to normal after a meal, insulin is no longer
secreted. -Answer A Positive feedback occurs when a stimulus causes an increased
response. Choices (B), (C), and (D) are examples of negative feedback.
A large island is devastated by a volcanic eruption. Most of the horses die except for the
heaviest males and heaviest females of the group. They survive, reproduce, and
perpetuate the population. Since weight is highly heritable and the distribution of
weights approximates a binomial distribution, the offspring of the next generation would
be expected to have
A. a higher mean weight compared with their parents
B. a lower mean weight compared with their parents
C. the same mean weight as members of the original population
D. a higher mean weight compared with members of the original population -Answer
D The mean weight of the offspring in the next generation will be heavier than the mean
weight of the original population because all the lighter horses in the original population
died off. The normal distribution for weight will therefore shift to the heavier end (to the
right of the graph).
During the period when life is believed to have begun, the atmosphere on primitive
Earth contained abundant amounts of all the following gases EXCEPT
A. oxygen
B. hydrogen
C. ammonia
D. methane -Answer A The primitive atmosphere lacked oxygen (O2). It contained
methane (CH4), ammonia (NH3), and hydrogen (H2).
Villi and microvilli are present in the small intestine and aid in reabsorption by
A. increasing the surface area of the small intestine
B. decreasing the surface area of the small intestine
, C. making the small intestine more hydrophilic
D. making the small intestine more hydrophobic -Answer A Villi and microvilli are
fingerlike projections present in the small intestine that dramatically increase the surface
area available for nutrient absorption.
Which of the following does NOT take place in the small intestine?
A. Pancreatic lipase breaks down fats to fatty acids and glycerol.
B. Pepsin breaks down proteins to amino acids.
C. Pancreatic amylase breaks down carbohydrates into simple sugars.
D. Bile emulsifies fats into smaller fat particles. -Answer B Pepsin works in the
stomach (not the small intestine) to break down proteins to peptides. Complete
digestion occurs in the small intestine. Pancreatic lipase breaks down fats into three
fatty acids and glycerol, so eliminate (A). Pancreatic amylase breaks down
carbohydrates into simple sugars, so (C) can also be eliminated. Bile emulsifies lipids
and makes them more accessible to lipase, so get rid of (D).
In animal cells, which of the following represents the most likely pathway that a
secretory protein takes as it is synthesized in a cell? -Answer D Ribosomes are the
site of protein synthesis. Therefore, the correct Answer should start with ribosome.
So eliminate (A) and (C). The polypeptide then moves through the rough ER to the
Golgi apparatus, where it is modified and packaged into a vesicle. The vesicle then
floats to the plasma membrane and is secreted. Choice (D) is your Answer.
Which of the following adaptive features would least likely be found in an animal living in
a hot arid environment?
A. Long loops of Henle to maximize water reabsorption
B. Storage of water in fatty tissues
C. Large ears to aid in heat dispersion
D. Short loops of Henle to maximize water secretion -Answer D The main challenge
for organisms residing in hot arid environments is water loss. Long loops of Henle and
storage of water in fatty tissues conserve water resources and large ears help disperse
heat. Secretion is the elimination of water in the kidneys, which would not be
advantageous for an organism in a dry environment.
Which of the following best accounts for the ability of legumes to grow well in nitrogen-
poor soils?
A. These plants make their own proteins.
B. These plants have a mutualistic relationship with nitrogen-fixing bacteria.
C. These plants are capable of directly converting nitrogen gas into nitrates.
D. These plants do not require nitrogen to make plant proteins. -Answer B Legume
plants are able to live in nitrogen-poor soil because they obtain nitrogen from nitrogen-
With Over 250 Most Tested
Questions And Correct
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The resting membrane potential depends on which of the following?
I. Active transport
II. Selective permeability
III. Differential distribution of ions across the axonal membrane
A. III only
B. I and II only
C. II and III only
D. I, II, and III -Answer D The resting potential depends on active transport (the
Na+K+-ATPase pump) and the selective permeability of the axon membrane to K+ than
to Na+, which leads to a differential distribution of ions across the axonal membrane.
The Krebs cycle in humans occurs in the
A. mitochondrial matrix
B. inner mitochondrial membrane
C. outer mitochondrial membrane
D. intermembrane space -Answer A The Krebs cycle occurs in the mitochondrial
matrix. Don't forget to review the site of each stage of aerobic respiration. Glycolysis,
the first step in aerobic respiration, occurs in the cytoplasm. The electron transport
chain occurs along the inner mitochondrial membrane. Oxidative phosphorylation
occurs as protons (H+ ions) move from the intermembrane space to the mitochondrial
matrix.
A heterotroph
A. obtains its energy from sunlight, harnessed by pigments
B. obtains its energy by oxidizing organic molecules
C. makes organic molecules from CO2
D. obtains its energy by consuming exclusively autotrophs -Answer B A heterotroph
obtains its energy from organic molecules. An autotroph obtains energy from sunlight
utilizing pigments such as chlorophyll, and uses CO2 and water to make organic
,molecules. Therefore, (A) and (C) can be eliminated. Heterotrophs can obtain their
energy from ingesting autotrophs, but they can also consume other heterotrophs.
Regarding meiosis and mitosis, one difference between the two forms of cellular
reproduction is that in meiosis
A. there is one round of cell division, whereas in mitosis there are two rounds of cell
division
B. separation of sister chromatids occurs during the second division, whereas in mitosis
separation of sister chromatids occurs during the first division
C. chromosomes are replicated during interphase, whereas in mitosis chromosomes are
replicated during prophase
D. spindle fibers form during prophase, whereas in mitosis the spindle fibers form during
metaphase -Answer B In meiosis, the sister chromatids separate during the second
metaphase of meiosis (Meiosis II), whereas the sister chromatids separate during
metaphase of mitosis.
A feature of amino acids NOT found in carbohydrates is the presence of
A. carbon atoms
B. oxygen atoms
C. nitrogen atoms
D. hydrogen atoms -Answer C Amino acids are organic molecules that contain
carbon, hydrogen, oxygen, and nitrogen, so eliminate (A), (B), and (D). Don't forget to
associate amino acids with nitrogen because of the amino group (NH2).
Which of the following is NOT a characteristic of bacteria?
A. Circular double-stranded DNA
B. Membrane-bound cellular organelles
C. Plasma membrane consisting of lipids and proteins
D. Ribosomes that synthesize polypeptides -Answer B Unlike eukaryotes,
prokaryotes (which include bacteria) do not contain membrane-bound organelles.
Bacteria contain circular double-stranded DNA, ribosomes, and a cell wall, so (A) and
(D) are incorrect. Also eliminate (C) because bacterial cell membranes are made up of a
bilipid layer with proteins interspersed.
Which of the following best explains why a population is described as the evolutionary
unit?
A. Genetic changes can only occur at the population level.
B. The gene pool in a population remains fixed over time.
C. Natural selection affects individuals, not populations.
D. Individuals cannot evolve, but populations can. -Answer D Populations can be
described as the evolutionary unit because changes in the genetic makeup of
,populations can be measured over time. Eliminate (A), as genetic changes occur only at
the individual level. Only under Hardy-Weinberg equilibrium does the gene pool remain
fixed over time in a population. However, this statement does not explain why the
population is the evolving unit, so (B) is incorrect. Choice (C) is true but does not
address the question.
The endocrine system maintains homeostasis using many feedback mechanisms.
Which of the following is an example of positive feedback?
A. Infant suckling causes a mother's brain to release oxytocin, which in turn stimulates
milk production.
B. An enzyme is allosterically inhibited by the product of the reaction it catalyzes.
C. When ATP is abundant the rate of glycolysis decreases.
D. When blood sugar levels decrease to normal after a meal, insulin is no longer
secreted. -Answer A Positive feedback occurs when a stimulus causes an increased
response. Choices (B), (C), and (D) are examples of negative feedback.
A large island is devastated by a volcanic eruption. Most of the horses die except for the
heaviest males and heaviest females of the group. They survive, reproduce, and
perpetuate the population. Since weight is highly heritable and the distribution of
weights approximates a binomial distribution, the offspring of the next generation would
be expected to have
A. a higher mean weight compared with their parents
B. a lower mean weight compared with their parents
C. the same mean weight as members of the original population
D. a higher mean weight compared with members of the original population -Answer
D The mean weight of the offspring in the next generation will be heavier than the mean
weight of the original population because all the lighter horses in the original population
died off. The normal distribution for weight will therefore shift to the heavier end (to the
right of the graph).
During the period when life is believed to have begun, the atmosphere on primitive
Earth contained abundant amounts of all the following gases EXCEPT
A. oxygen
B. hydrogen
C. ammonia
D. methane -Answer A The primitive atmosphere lacked oxygen (O2). It contained
methane (CH4), ammonia (NH3), and hydrogen (H2).
Villi and microvilli are present in the small intestine and aid in reabsorption by
A. increasing the surface area of the small intestine
B. decreasing the surface area of the small intestine
, C. making the small intestine more hydrophilic
D. making the small intestine more hydrophobic -Answer A Villi and microvilli are
fingerlike projections present in the small intestine that dramatically increase the surface
area available for nutrient absorption.
Which of the following does NOT take place in the small intestine?
A. Pancreatic lipase breaks down fats to fatty acids and glycerol.
B. Pepsin breaks down proteins to amino acids.
C. Pancreatic amylase breaks down carbohydrates into simple sugars.
D. Bile emulsifies fats into smaller fat particles. -Answer B Pepsin works in the
stomach (not the small intestine) to break down proteins to peptides. Complete
digestion occurs in the small intestine. Pancreatic lipase breaks down fats into three
fatty acids and glycerol, so eliminate (A). Pancreatic amylase breaks down
carbohydrates into simple sugars, so (C) can also be eliminated. Bile emulsifies lipids
and makes them more accessible to lipase, so get rid of (D).
In animal cells, which of the following represents the most likely pathway that a
secretory protein takes as it is synthesized in a cell? -Answer D Ribosomes are the
site of protein synthesis. Therefore, the correct Answer should start with ribosome.
So eliminate (A) and (C). The polypeptide then moves through the rough ER to the
Golgi apparatus, where it is modified and packaged into a vesicle. The vesicle then
floats to the plasma membrane and is secreted. Choice (D) is your Answer.
Which of the following adaptive features would least likely be found in an animal living in
a hot arid environment?
A. Long loops of Henle to maximize water reabsorption
B. Storage of water in fatty tissues
C. Large ears to aid in heat dispersion
D. Short loops of Henle to maximize water secretion -Answer D The main challenge
for organisms residing in hot arid environments is water loss. Long loops of Henle and
storage of water in fatty tissues conserve water resources and large ears help disperse
heat. Secretion is the elimination of water in the kidneys, which would not be
advantageous for an organism in a dry environment.
Which of the following best accounts for the ability of legumes to grow well in nitrogen-
poor soils?
A. These plants make their own proteins.
B. These plants have a mutualistic relationship with nitrogen-fixing bacteria.
C. These plants are capable of directly converting nitrogen gas into nitrates.
D. These plants do not require nitrogen to make plant proteins. -Answer B Legume
plants are able to live in nitrogen-poor soil because they obtain nitrogen from nitrogen-
