Which of the following types of molecules are the major structural components of the celll membrane?
phospholipids, proteins, and cellulose
phospholipids, nucleic acids, and proteins
phospholipids and proteins only
phospholipids, proteins, and cholesterol
glycoproteins and cholesterol
which of the following most accurately describes selective permeability?
an input of energy is required for transport across the membrane
charged molecules pass through a membrane
there must be a concentration gradient for molecules to pass through a membrane
some molecules can cross a cell membrane, and others cannot
diffusion is an example of
phagocytosis
active transport
endocytosis
passive transport
glucose diffuses slowly through artificial phospholipid bilayers. the cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose-poor cytoplasm. using this information, which transport mechanism is most probably functioning in the intestinal cells?
simple diffusion
phagocytosis
active transport pumps
exocytosis
facilitated diffusion
what kinds of molecules pass through a cell membrane most easily?
large and hydrophobic
small and hydrophobic
large polar
ionic
monosaccharides such as glucose
A cell that neither gains nor loses water when it is immersed in a solution is
isotonic to its environment
hypertonic to its environment
hypotonic to its environment
metabolically inactive
Which of the following is true of osmosis?
osmosis only occurs in red blood cells
Osmosis is an energy-demanding or "active" process.
In osmosis, water moves across a membrane from areas of lower solute concentration to areas of
higher solute concentration.
In osmosis, solutes move across a membrane from areas of lower water concentration to areas of
higher water concentration.
Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45
M NaCl. What will happen if red blood cells are transferred to seawater?
Water will leave the cells, causing them to shrivel and collapse.
NaCl will be exported from the red blood cells by facilitated diffusion.
The blood cells will take up water, swell, and eventually burst.
NaCl will passively diffuse into the red blood cells.
The blood cells will expend ATP for active transport of NaCl into the cytoplasm.
Which of the following membrane activities require energy from ATP hydrolysis?
facilitated diffusion of chloride ions across the membrane through a chloride channel
movement of water into a cell by osmosis
Na+ ions moving out of a mammalian cell bathed in physiological saline (salt solution)
movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cells
movement of carbon dioxide out the paramecium
Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?
CO2
an amino acid
glucose
K+
starch
Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a 0.15 M salt solution become limp and soft. From this, what can we deduce about the cells of the celery stalks?
The cells are hypotonic to both fresh water and the salt solution.
The cells are hypertonic to both fresh water and the salt solution.
The cells are hypertonic to fresh water but hypotonic to the salt solution.
The cells are hypotonic to fresh water but hypertonic to the Salt solution.
The cells are isotonic with fresh water but hypotonic to the salt solution.
An organism with a cell wall would most likely be unable to take in materials through which of the following process?
diffusion
osmosis
active transport
phagocytosis
facilitated diffusion
What is energy?
the capacity to cause movement
the capacity to cause change
a measure of calories
a measure of disorder
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
catalysis
metabolism
anabolism
dehydration
catabolism
Which of the following is a statement of the first law of thermodynamics?
energy cannot be created or destroyed
The entropy of the universe is decreasing.
The entropy of the universe is constant.
Kinetic energy is stored energy that results from the specific arrangement of matter.
Energy cannot be transferred or transformed.
Which of the following is an example of potential rather than kinetic energy?
the muscle contractions of a person mowing grass
water rushing over Niagara Falls
light flashes emitted by a firefly
a molecule of glucose
the flight of an insect foraging for food
How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?
by binding at the active site of the enzyme, blocking it.
by binding elsewhere and changing the shape of the enzyme's active site.
Which of the following is (are) true for anabolic pathways?
They do not depend on enzymes.
They are usually highly spontaneous chemical reactions.
They consume energy to build up polymers from monomers.
They release energy as they degrade polymers to monomers.
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?
it is used for power yet more cellular work
It is used to store energy as more ATP.
It is used to generate ADP from nucleotide precursors.
It is lost to the environment.
It is transported to specific organs such as the brain.
Which of the following statements is representative of the second law of thermodynamics?
Conversion of energy from one form to another is always accompanied by some gain of free energy
Heat represents a form of energy that can be used by most organisms to do work.
Without an input of energy, organisms would tend toward higher levels of organization.
Cells require a constant input of energy to maintain their high level of organization.
According to the induced-fit hypothesis of enzyme catalysis, which of the following is correct?
The binding of the substrate depends on the shape of the active site.
Some enzymes change their structure when activators bind to the enzyme.
A competitive inhibitor can outcompete the substrate for the active site.
The binding of the substrate changes the shape of the enzyme's active site.
The waste products of cellular respiration include _
water only
carbon dioxide only
water and carbon dioxide
water and glucose
Where does glycolysis take place in eukaryotic cells?
mitochondrial matrix
mitochondrial outer membrane
mitochondrial inner membrane
mitochondrial inter membrane space
cytoplasm
In addition to ATP, what are the end products of glycolysis?
CO2 and H20
CO2 and pyruvic acid
NADH and pyruvic acid
CO2 and NADH
H2O, FADH2, and citric acid
Carbon dioxide (CO) is released during which of the following stages of cellular respiration?
glycolysis and the transition reaction.
transition reaction and the citric acid cycle
the citric acid cycle and electron transport chain
glycolysis, the transition reaction, the citric acid cycle and the electron transport chain.
Where are the proteins of the electron transport chain located?
cytosol
mitochondrial outer membrane
mitochondrial inner membrane
mitochondrial inter membrane space
mitochondrial matrix
Which of the following statements describes the results of this reaction?
C6H1206 + 602 → 6 CO2 + 6H20 + Energy
C6H1206 is oxidized and 02 is reduced.
O2 is oxidized and H20 is reduced.
CO2 is reduced and 02 is oxidized.
C6H1206 is reduced and CO2 is oxidized.
O2 is reduced and CO2 is oxidized.
How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of the transition reaction of one glucose?
two
four
six
eight
ten
Which process in eukaryotic cells will proceed normally whether oxygen (O) is present or absent?
electron transport
glycolysis
citric acid cycle
transition reaction
The oxygen consumed during cellular respiration is involved directly in which process or event?
glycolysis
accepting electrons at the end of the electron transport chain
fermentation
the phosphorylation of ADP to form ATP
During glycolysis, when each molecule of glucose is catabolized to two molecules of pyruvate, what happens to most of the potential energy contained in glucose?
It is transferred to ADP, forming ATP.
It is transferred directly to ATP.
It is retained in the two pyruvates.
It is stored in the NADH produced.
It is used to phosphorylate fructose to form fructose 6-phosphate.
What fraction of the carbon dioxide exhaled by animals is generated by the reactions of the citric acid cycle, if glucose is the sole energy source?
1/6
1/3
2/3
100/100
Name the process prokaryotes use to make exact copies of themselves.
If there are 20 chromosomes in a non-dividing cell, how many sister chromatids are there at the start
of mitosis?
10
20
30
40
80
At which phase are sister chromatids beginning to move apart in animal cells?
telophase
anaphase
metaphase
prophase
What phase of the cell cycle is this?
spindle fibers grabbing cell in the middle
interphase
prophase
metaphase
anaphase
telophase
The cell cycle results in the production of
four cells, each with the same amount of genetic material and the same genetic information
two cells, each with the same amount of genetic material but with different genetic information
two cells, each with the same amount of genetic material and the same genetic information
four cells, each with the same amount of genetic material but with different genetic information
What occurs at the centromere?
sister chromatids remain attached to one another here until anaphase
DNA copying starts at centromeres
chromosomes are grouped around centromeres during telophase
new spindle microtubules form at centromeres
Why do neurons and some other specialized cells divide infrequently?
They no longer have active nuclei.
They no longer have DNA inside.
They have been shunted into Go.
A cell that completed the cell cycle without undergoing cytokinesis would
A) have less genetic material than it started with
not have completed anaphase
have its chromosomes lined up in the middle of the cell
have two nuclei
Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells?
4
8
16
32
64
In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common?
length and position of centromere only
length, centromere position, and staining pattern only
length, centromere position, staining pattern, and traits coded for by their genes
They have nothing in common except that they are X-shaped.
What chromosomes belong to a normal human male?
22 autosomes and two Y chromosomes
44 autosomes and two Y chromosomes
44 autosomes, one X chromosome, and one Y chromosome
46 autosomes, one X chromosome, and one Y chromosome
Homologous chromosomes
are identical
carry information for the same traits in the same place
carry the same alleles (have matching genes)
align on the metaphase plate in meiosis II
Which of the following happens at the conclusion of meiosis I?
Homologous chromosomes of a pair are separated from each other.
Another interphase
Sister chromatids are separated.
Four daughter cells are formed.
A ____ describes a site of crossing over.
chiasma
histone
synapsr
centromere
The human X and Y chromosomes
are missing in those with Kleinfelter syndrome
are the same size and have the same number of genes
include genes that determine an individual's biological sex
are called autosomes
Which of the following occurs in meiosis but not in mitosis?
chromosome replication in the S phase
synapsis (crossing over) of chromosomes
alignment of chromosomes at the equator
breaking of the centromere
Which of the following is true of a species that has a chromosome number of 2n = 16?
The species is diploid with 32 chromosomes per cell.
The species has 16 sets of chromosomes per cell.
Each diploid cell has eight homologous pairs.
A gamete from this species has four chromosomes.
Which of the following is a characteristic seen in prophase I that does not occur in prophase II?