BSC 1010 Final Exam Review
at which phase of the cell cycle do centrioles of the aster begin to move apart in animal cells?
prophase
Diffusion of ions across membranes through specific ion channels is driven by ________.
ion electrochemical gradients
which of the following is not apart of the endomembrane system?
chloroplast
Which curve represents the behavior of an enzyme taken from a bacterium that lives in hot springs at temperatures of 70°C or higher?
curve 3
Which curve was most likely generated from analysis of an enzyme from a human stomach where conditions are strongly acid?
curve 4
What compound is found at the reaction center of a photosystem?
chlorophyll a
One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called?
translocation
The voltage across a membrane is called the _______.
membrane potential
In its mechanism, photophosphorylation is most similar to _____.
substrate-level phosphorylation in glycolysis
Why do neurons and some other specialized cells divide infrequently?
they have entered into G0.
which of the following statements correctly describes catabolic pathways?
they release energy as they degrade polymers to monomers
which of the following is an example of monosomy in humans?
turner syndrome
In a diploid cell with 5 chromosome pairs (2n=10), how many centromeres will be found in a nucleus at G2 of the cell division cycle?
10
how many chromosomes does an individual with Turner syndrome have?
2n-1
approximately what percentage of the energy of glucose is transferred to storage in ATP is a result of the complete oxidation of glucose to CO2 and water in cellular respiration?
40%
which of the following statements about a G-protein signaling pathway is true?
A G protein bound to GTP is in its active state.
what are the final products of linear/ noncyclic electron flow?
ATP and NADPH
which of the following are products of the light reactions of photosynthesis that are used in the Calvin Cycle?
ATP and NADPH
What does cyclic electron flow in the chloroplast produce?
ATP only
The first step of the Calvin cycle is the incorporation of ______ into ______.
CO2 . . . RuBP
Eukaryotic chromosomes are composed of which of the following macromolecules?
DNA and proteins
Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue. Cell A is most likely in
G1
the endomembrane system includes _______
Golgi apparatus, lysosomes, vacuoles, and the endoplasmic reticulum
________ is the source of the oxygen gas released by a photosystem.
H2O
which of the following sequences correctly represents the flow of electrons during photosynthesis?
H2O ---> NADPH ---> Calvin Cycle
the final electron acceptor associated with photosystem I is _________.
NADP
which molecule donates electrons in photosynthesis?
Water
All the organisms on your campus make up
a community
which of the following statements defines a genome?
a complete set of an organism's genes and other DNA sequences
What wavelengths of light should be used to maximize plant growth with a minimum of energy expenditure?
a mixture of blue and red light
Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely
a plant cell in the process of cytokinesis
which process could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than its surroundings?
active transport
In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?
aggregation of bacteria that can cause cavities
during which phase do the chromatids become chromosomes?
anaphase
during which of the following phases of meiosis do homologous chromosomes separate?
anaphase I
during which of the following phases of meiosis do centromeres split and sister chromatids migrate to opposite poles of the cell?
anaphase II
in the cells of many eukaryotic species, the nuclear envelope has to disappear to permit which of the following events in the cell?
attachment of the spindle fiber to kinetochores
how does a competitive inhibitor decrease the rate of an enzyme reactiob
by binding at the active site of the enzyme
how does a non-competitive inhibitor decrease the rate of an enzyme reaction?
by changing the structure of the enzyme
which molecule accepts electrons in photosynthesis?
carbon dioxide
what is a nonprotein "helper" of an enzyme molecule called?
coenzyme
Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a(n)
cofactor necessary for enzyme activity
in a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and _____
combine the hydrogen with oxygen molecules to generate hydrogen peroxide
What two components constitute an active MPF?
cyclin and a cyclin-dependent kinase
which of the following processes occur during meiosis but not mitosis?
diploid cells form haploid cells
Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to
disruption of mitotic spindle formation
which of the following is a statement of the first law of thermodynamics?
energy can neither be created or destroyed.
Catabolism is to anabolism as __________ is to __________.
exergonic; endergonic
When a person cries, tears are exported from cells through the process of ________.
exocytosis
specialized cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. which process could be responsible for its secretion?
exocytosis
__________. is a regulatory mechanism in which the end product of a metabolic pathway inhibits an enzyme that catalyzes an early step in the pathway.
feedback inhibition
the mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as
feedback inhibition
CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they
fix CO2 into organic acids during the night.
which molecule donates electrons in cellular respiration?
glucose
Hormones are chemical substances produced in one organ that are released into the bloodstream and affect the function of a target organ. For the target organ to respond to a particular hormone, it must _____.
have receptors that recognize and bind to the hormone molecule
which of the following distinguishes a hypothesis from a theory in science?
hypothesis usually are relatively narrow in scope; theories have broad explanatory power
during which of the following processes does independent assortment of chromosomes occur?
in meiosis I only
which of the following statements correctly describes osmosis?
in osmosis, WATER moves across a membrane from areas of lower solute concentration to areas of higher water concentration.
which of the following statements is correct in comparing sexual and asexual reproduction?
in sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring
the membranes of winter wheat are able to remain fluid when it is extremely cold ____________
increasing the proportion of unsaturated phospholipids in the membrane
what is the most likely mechanism by which testosterone functions inside a cell?
it binds with a receptor protein that enters the nucleus and activates expression of specific genes.
which of the following statements about diffusion is true?
it is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.
which of the following statements correctly describes a karyotype?
it is an organized image of a cell's chromosomes
If a cell has completed meiosis I and is just beginning meiosis II, which of the following is an appropriate description of its contents?
it is half the amount of DNA as the cell that began meiosis
why is STP an important molecule in metabolism?
it provides. energy coupling between exergonic and endergonic reactions.
what is the function of the nuclear pore complex found in eukaryotic cells?
it regulates the movement of proteins and RNAs into and out of the cell.
One primary advantage of light microscopy over electron microscopy is that ________.
light microscopy allows the visualization of dynamic processes in living cells
a bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in ________.
lysosomes
nondisjunction might result in games with the chromosome numbers ___________.
n+1 or n-1
inheritance patterns cannot always be explained by Mendel's models of inheritance. If a pair of homologous chromosomes fails to separate during meiosis I, select the choice that shows the chromosome number of the four resulting gametes with respect to the normal haploid number (n).
n+1; n+1; n-1; n-1
a molecule that accepts an electron is called a __________ agent.
oxidizing
which molecule accepts electrons in cellular respiration?
oxygen
which of the following is a type of local signaling in which a cell secretes a signal molecule that affects neighboring cells?
paracrine signaling
which of the following processes includes all of the others?
passive transport
white blood cells engulf bacteria using
phagocytosis
the difference between pinocytosis and receptor-mediated endocytosis is that ___________.
pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity
what is the oxidizing agent in the following reaction? Pyruvate+NADH+ H^+ -----> Lactate+NAD^+
pyruvate
One of the major categories of receptors in the plasma membrane reacts by forming dimers, adding phosphate groups, and then activating relay proteins. Which type does this?
receptor tyrosine kinases
which of the following does NOT occur during the Calvin Cycle?
release of oxygen
which of the following does not occur during mitosis
replication of DNA
which of the following are found in plant, animal , and bacterial cells?
ribosomes
which of the following is a common pathway taken by newly synthesized protein that will be secreted by a cell?
rough ER -> Golgi -> transport vesicle -> PM
When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?
signal molecule
how many times must the Calvin cycle turn for the plant cell to produce one molecule of glucose?
six
when oxygen is released as a result of photosynthesis, it is a direct by-product of
splitting water molecules
which of the following would be the most appropriate method to observe the movements of condensed chromosomes during cell division?
standard light microscopy
what is the function of the Calvin Cycle?
synthesize simple sugars from carbon dioxide
a controlled experiment is one that _________
tests experimental and control groups in parallel
what will happen to a RBC, which has an internal solute content of about 0.9%, if it is placed into a beaker of pure water?
the cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC.
which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I?
the cells are haploid, and the chromosomes ate each composed of two chromatids
which of the following statements is a reasonable explanation for why unsaturated fatty acids help keep a membrane more fluid at lower temperatures?
the double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly.
genetic variation is accomplished by all but one of the following. Chose the EXCEPTION.
the events of meiosis II
which of the following is an example of qualitative data?
the fish swam in a zigzag motion
which of these best demonstrates unity among all organisms?
the structure and function of DNA
Some bacteria are metabolically active in hot springs because
their enzymes have high optimal temperatures
which of the following characteristics do homologous chromosomes exihibit?
they carry information for the same traits
which of the following statements about anabolic pathways is true
they consume energy to build up polymers from monomers.
Why are C4 plants able to photosynthesize with no apparent photorespiration?
they use PEP carboxylase to initially fix CO2.
Systems biology is mainly an attempt to
understand the behavior of entire biological systems by studying interactions among its component parts
how many molecules of glucose are produced by each cycle of the light rxn?
zero