BIOL Midterm 2
Number of FADH2 from one pyruvate molecules?
1
Number of pyruvate molecules from five glucose molecules in glycolysis?
10
Total number of ATP produced by substrate level phosphorylation of 2 glucose molecules during aerobic respiration?
12
Total number of ATP produced by substrate level phosphorylation of 2 glucose molecules during aerobic respiration?
12
Approximate number of ATP from 10 FADH2 molecules?
15
Net ATP produced by substrate level phosphorylation in Krebs cycle from 2 Acetyl CoA?
2
Net ATP produced by substrate level phosphorylation in Krebs cycle from 2 pyruvate?
2
Net ATP produced by substrate level phosphorylation in the Citric Acid cycle from 2 pyruvate?
2
If there are 20 homologous pairs of chromosomes in a sexually reproducing organism, how many chromosomes are in one gamete?
20
Approximate number of ATP from 10 NADH molecules?
25
Number of NADH in matrix from one AcetylCoA?
3
Place the following events in their sequential order: 1. protein kinase A is activated 2. glycogen breakdown 3. epinephrine binds to G-protein-linked receptor 4. G-protein activates adenylyl cyclase 5. GTP is exchanged for GDP on the G-protein 6. ATP is converted to cAMP
3, 5, 4, 6, 1, 2
Number of FADH2 from four pyruvate molecules?
4
Number of NADH in matrix from one pyruvate in the matrix?
4
Number of pyruvate molecules from two glucose molecules in glycolysis?
4
Total number of NADH during glycolysis of two glucose molecules?
4
Number of NADH in matrix from two acetyl CoA?
6
Total number of ATP produced by substrate level phosphorylation of a glucose molecule during aerobic respiration (glycolysis+Krebs cycle)?
6
Total number of ATP produced by substrate level phosphorylation of a glucose molecule during aerobic respiration (glycolysis+Krebs cycle)?
6
Total number of NADH during glycolysis of three glucose molecules?
6
Number of NADH in matrix from two pyruvate in the matrix?
8
A cell containing 92 chromatids at metaphase of mitosis would, at its completion, produce two nuclei containing how many chromosomes?
92 / 2 = 46
A signal molecule is also known as a(n) _____. A. ligand B. protein C. initiator D. key E. receptor
A
A toxin that inhibits the production of GTP would interfere with the function of a signal transduction pathway that is initiated by the binding of a signal molecule to _____ receptors. A. G-protein-linked B. ion-channel C. intracellular D. steroid E. receptor tyrosine kinase
A
CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they A. fix CO2 into organic acids during the night. B. fix CO2 into sugars in the bundle-sheath cells. C. fix CO2 into pyruvate in the mesophyll cells. D. use the enzyme phosphofructokinase, which outcompetes rubisco for CO2 . E. use photosystems I and II at night.
A
Cytokinesis often, but not always, accompanies _____. A. telophase B. prometaphase C. metaphase D. anaphase E. interphase
A
During electron transport, energy from _____ is used to pump hydrogen ions into the __________. A. NADH and FADH2 ... intermembrane space B. NADH and FADH2 ... mitochondrial matrix C. NADH ... intermembrane space D. NADH ... mitochondrial matrix E. acetyl CoA ... intermembrane space
A
During interphase the genetic material of a typical eukaryotic cell is _____. A. found as long strands of chromatin in the nucleus B. found as long strands of chromatin in the cytoplasm C. condensed to rod-like chromosomes D. attached to microtubule spindle fibers E. transported through the nuclear pores
A
From the perspective of the cell receiving the message, the three stages of cell signaling are A. signal reception, signal transduction, and cellular response. B. the paracrine, local, and synaptic stages. C. signal reception, nucleus disintegration, and new cell generation. D. the alpha, beta, and gamma stages. E. signal reception, cellular response, and cell division.
A
How many maternal chromosomes are present in a somatic human cell in G1 phase of the cell cycle? A. 23 B. 46 C. 92 D. 184
A
How many maternal chromosomes are present in a somatic human cell in G1 phase of the cell cycle? A. 23 B. 46 C. 92 D. 184
A
Human males typically have XY chromosomes and females have XX chromosomes, but there are rare instances in which a male can inherit an XXY or an XYY, or a female can have three X chromosomes. Explain how an error in meiosis can cause these aberrations. A. Aberrations caused when a pair of homologous chromosomes fails to separate during anaphase I or when sister chromatids fail to separate during anaphase II, the daughter cells will inherit unequal numbers of chromosomes. B. Errors during meiosis introduce variations in the DNA sequence, which depends specifically on the size of the variant only. C. Errors can arise only during the recombination process which may result in deletions, duplications or translocations causing such abnormalities. D. Errors during anaphase I of meiosis only cause such aberrations resulting in unequal numbers of chromosomes.
A
If there are 20 chromatids in a cell at metaphase, how many chromosomes are there in each daughter cell following cytokinesis? A. 10 B. 20 C. 30 D. 40 E. 80
A
If there are 20 chromatids in a cell at metaphase, how many chromosomes are there in each daughter cell following cytokinesis? A. 10 B. 20 C. 30 D. 40 E. 80
A
In the cells of some organisms, mitosis occurs without cytokinesis. This will result in A. cells with more than one nucleus B. cells that are unusually small C. cells lacking nuclei D. destruction of chromosomes E. cell cycles lacking an S phase
A
Paracrine signaling A. involves secreting cells acting on nearby target cells by discharging a local regulator into the extracellular fluid. B. requires nerve cells to release a neurotransmitter into the synapse. C. occurs only in paracrine yeast cells. D. has been found in plants but not animals. E. involves mating factors attaching to target cells and causing production of new paracrine cells.
A
Photosynthetically active radiation is A. Light in the 700 nm to 400 nm range. B. Light in the ultraviolet range. C. Light in the 900 nm to 225 nm range. D. Light in the infrared range.
A
Predict the end result if a chloroplast's light-independent enzymes developed a mutation that prevented them from activating in response to light A. ATP and NADPH accumulation B. Water accumulation C. Carbon dioxide depletion D. GA3P accumulation
A
Rubisco is _____. A. the enzyme in plants that first captures CO2 to begin the Calvin cycle B. the enzyme responsible for splitting H2O to produce O2 in photosynthesis C. the enzyme that forms a 4-carbon compound in CAM metabolism D. the first stable intermediate in CAM metabolism E. the 5-carbon sugar molecule that reacts with CO2 to begin the Calvin cycle
A
Sister chromatids separate during _____. A. anaphase B. G1 phase C. G2 phase D. metaphase E. prophase
A
The function of the cell cycle is to produce daughter cells that _____. A. are genetically identical to the parent cell (assuming no mutation has occurred) B. have the same number of chromosomes as the parent cell but not the same genetic content C. have a random assortment of maternal and paternal chromosomes D. have the same number of chromatids as the parent cell had chromosomes E. none of the above
A
What does the chemiosmotic process in chloroplasts involve? A. establishment of a proton gradient B. diffusion of electrons through the thylakoid membrane C. reduction of water to produce ATP energy D. movement of water by osmosis into the thylakoid space from the stroma E. formation of glucose, using carbon dioxide, NADPH, and ATP
A
When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by _____. A. splitting water B. breaking down ATP C. removing them from NADPH D. fixing carbon E. oxidizing glucose
A
Where are the proteins of the electron transport chain located? A. mitochondrial inner membrane B. mitochondrial intermembrane space C. mitochondrial outer membrane D. mitochondrial matrix E. cytosol
A
Where does the Calvin cycle take place? A.stroma of the chloroplast B.thylakoid membrane C.cytoplasm surrounding the chloroplast D.chlorophyll molecule E.outer membrane of the chloroplast
A
You would know a dividing cell was a plant cell rather than an animal cell if you saw that _____. A. it had formed a cell plate B. it had two pairs of centrioles during prophase C. it had microtubules D. the nucleolus was visible during metaphase E. it had formed a cleavage furrow
A
Three of the same species of plant are each grown under a different colored light for the same amount of time. Plant A is grown under blue light, Plant B is grown under green light, and Plant C is grown under orange light. Assuming the plants use only chlorophyll a and chlorophyll b for photosynthesis, what would be the predicted order of the plants from most growth to least growth
A, C, B
A single diploid cell with 22 chromosomes undergoes meiosis and produces gametes. Describe the cells produced. A. The result would be one cell with 22 chromosomes. B. The result would be four cells, each containing 11 chromosomes. C. Meiosis cannot occur on a diploid cell. D. The result would be four cells, each containing 22 chromosomes.
B
A small molecule that specifically binds to a larger molecule is called a(n) _____. A. α- protein B. ligand C. protein kinase D. competitive inhibitor E. DAG
B
At which stage of mitosis are chromosomes lined up in one plane in preparation for their separation to opposite poles of the cell? A. prophase B. metaphase C. anaphase D. telophase E. interphase
B
Carbon monoxide binds to cytochrome c oxidase (complex IV) in the electron transport chain. This results in carbon monoxide competitively inhibiting complex IV from functioning. Which of the is NOT directly affected by this inhibition? A. Reduction of oxygen B. Glycolysis C. Chemiosmosis D. Formation of water
B
Cells will usually divide if they receive the proper signal at a checkpoint in the _____ phase of the cell cycle. A. M B. G1 C. S D. G2 E. cytokinesis
B
Cooperation of the two photosystems is required for A. ATP synthesis. B. reduction of NADP+. C. cyclic photophosphorylation. D. oxidation of the reaction center of photosystem I. E. generation of a proton-motive force.
B
Describe what occurs at the M checkpoint and predict what would happen if the M checkpoint failed. A. The M checkpoint checks if the DNA is damaged and promotes its repair. If it fails, then the daughters end up with damaged DNA. B. The M checkpoint checks for proper attachment of sister chromatids and if it fails, then cells may undergo nondisjunction of chromosomes. C. The M checkpoint ensures the proper duplication of DNA and if it fails, the cells may undergo nondisjunction of chromosomes. D. The M checkpoint ensures that all the components required for cell division are available and if it fails, the cell cycle will be inhibited.
B
Drosophila melanogaster (fruit fly) has 4 pairs of chromosomes (2n=8) in its somatic cells. How many chromosomes are in one gamete? A. 2 B. 4 C. 6 D. 8
B
During Anaphase I of meiosis: A. Chromosomes align on the metaphase plate. B. Homologous chromosomes separate. C. Sister chromatids separate. D. The cleavage furrow forms . E. homologous chromatids form tetrads.
B
During fermentation reactions, which of the following best describes what happens to NADH? A. Phosphorylated B. Oxidized C. A gradient is formed D. Reduced
B
During photosynthesis in chloroplasts, O2 is produced from ______ via a series of reactions associated with ______. A. CO2 ... photosystem II B. H2O ... photosystem II C. CO2 ... Calvin cycle D. H2O ... photosystem I E. CO2 ... both photosystem I and the Calvin cycle
B
During respiration in a eukaryotic cell, reactions of the citric acid cycle occur _____. A. in the cytosol B. in the matrix of the mitochondrion C. in the cristae of the mitochondrion D. in the intermembrane space of the mitochondrion E. across the inner membrane of the mitochondrion
B
During what phase in the cell cycle would you find the most DNA amount per cell? A. G1 B. G2 C. S1 D. S E. prophase II
B
Fungi typically display which type of life cycle? A. alternation of generations B. haploid-dominant C. asexual D. diploid-dominant
B
High levels of ADP ____. A. have no effect on the activity of any enzymes involved with glycolysis B. increase the activity of enzymes involved with glycolysis C. slow down all pathways involved with glycolysis D. decrease the activity of enzymes involved with glycolysis
B
How many pairs of autosomes do humans have? A. 23 B. 22 C. 2 D. 1 E. It depends on the sex of the individual.
B
Human males typically have XY chromosomes and females have XX chromosomes, but there are rare instances in which a male can inherit an XXY or an XYY, or a female can have three X chromosomes. Explain how an error in meiosis can cause these aberrations. A. Errors during anaphase I of meiosis only cause such aberrations resulting in unequal numbers of chromosomes. B. Aberrations caused when a pair of homologous chromosomes fails to separate during anaphase I or when sister chromatids fail to separate during anaphase II, the daughter cells will inherit unequal numbers of chromosomes. C. Errors can arise only during the recombination process which may result in deletions, duplications or translocations causing such abnormalities. D. Errors during meiosis introduce variations in the DNA sequence, which depends specifically on the size of the variant only.
B
Human males typically have XY chromosomes and females have XX chromosomes, but there are rare instances in which a male can inherit an XXY or an XYY, or a female can have three X chromosomes. Explain how an error in meiosis can cause these aberrations. A. Errors during meiosis introduce variations in the DNA sequence, which depends specifically on the size of the variant only. B. Aberrations caused when a pair of homologous chromosomes fails to separate during anaphase I or when sister chromatids fail to separate during anaphase II, the daughter cells will inherit unequal numbers of chromosomes. C. Errors can arise only during the recombination process which may result in deletions, duplications or translocations causing such abnormalities. D. Errors during anaphase I of meiosis only cause such aberrations resulting in unequal numbers of chromosomes.
B
If a cell contains 60 chromatids at the start of mitosis. How many chromosomes will be in each daughter cell when the cell cycle is completed? A. 15 B. 30 C. 45 D. 60 E. 120
B
In the Calvin cycle, CO2 is combined _____. A. with a 2-carbon compound to form a 3-carbon compound B. with a 5-carbon compound to form an unstable 6-carbon compound, which decomposes into two 3- carbon compounds C. with a 7-carbon compound to form two 4-carbon compounds D. with a 5-carbon compound to form a stable 6-carbon compound that can be converted directly to glucose E. with two 2-carbon compounds to form a 5-carbon compound
B
It is difficult to observe individual chromosomes with a light microscope during interphase because _____. A.the DNA has not been replicated yet B.they have uncoiled to form long, thin strands C.they leave the nucleus and are dispersed to other parts of the cell D.sister chromatids do not pair up until division starts E.the spindle must move them to the metaphase plate before they become visible
B
Many farmers are worried about the decreasing genetic diversity of plants associated with generations of artificial selection and inbreeding. Why is limiting random sexual reproduction of food crops concerning? A. Mutations during asexual reproduction decrease plant fitness. B. Larger portions of the plant populations are susceptible to the same diseases.Consumers do not trust identical-appearing produce. C. Spores are not viable in an agricultural setting. D. Consumers do not trust identical-appearing produce.
B
Molecular oxygen is produced during _____. A.glycolysis B.light reactions of photosynthesis C.the Calvin cycle D.aerobic respiration E.electron transport chain
B
Name the processes that eukaryotic cell division and binary fission have in common. A. DNA duplication, division of cell organelles, division of the cytoplasmic contents B. DNA duplication, segregation of duplicated chromosomes, and division of the cytoplasmic contents C. segregation of duplicated chromosomes, formation of a septum, division of cell organelles D. formation of a septum, DNA duplication, division of the cytoplasmic contents
B
Predict the end result if a chloroplast's light-independent enzymes developed a mutation that prevented them from activating in response to light A. GA3P accumulation B. ATP and NADPH accumulation C. Water accumulation D. Carbon dioxide depletion
B
The cytochrome complex is used in ____. A. anaerobic glycolysis B. photosystem II and cellular respiration C. calvin cycle and carbon Fixation D. photosystem I
B
The function of an electron in the electron transport chain is to _____. A. transport NADH into the matrix B. power active transport of H+ C. reduce heme in complex III D. oxidize oxygen
B
The overall function of the Calvin cycle is _____. A. capturing sunlight B. making sugar C. producing carbon dioxide D. splitting water E. oxidizing glucose
B
The phase of mitosis during which the chromosomes move toward separate poles of the cell is _____. A. telophase B. anaphase C. metaphase D. prophase E. prometaphase
B
The primary role of oxygen in cellular respiration is to A. yield energy in the form of ATP as it is passed down the respiratory chain. B. act as an acceptor for electrons and hydrogen, forming water. C. combine with carbon, forming CO2. D. combine with lactate, forming pyruvate. E. catalyze the reactions of glycolysis.
B
The process of cellular respiration is ___________, and during it, glucose is _____________. A. endergonic; reduced B. exergonic; oxidized C. exergonic; reduced D. endergonic; oxidized
B
The reaction center, light-harvesting complexes, and primary electron acceptors that cluster in the thylakoid membrane form which structure? A. fluorescence center B. photosystem C. electron transport chain D. carbon-fixation unit E. electromagnetic spectrum
B
The reaction-center chlorophyll of photosystem I is known as P700 because A. there are 700 chlorophyll molecules in the center. B. this pigment is best at absorbing light with a wavelength of 700 nm. C. there are 700 photosystem I components to each chloroplast. D. it absorbs 700 photons per microsecond. E. the plastoquinone reflects light with a wavelength of 700 nm.
B
What does bioluminescence show about communication in bacteria? A. Bacterium interact by physical signals when it is alone. B. Bacteria interact by chemical signals among a colony. C. Bacterium interact by chemical signals when it is alone. D. Bacteria interact by physical signals among a colony
B
What is the name for the special region on a duplicated chromosome that holds the sister chromatids together? A. centrosome B. centromere C. kinetochore D. desmosome E. microtubule organizer region
B
What is the product of the Calvin cycle? A. Pyruvate B. Glyceraldehyde-3-Phosphate C. sucrose D. Phosphoglycerate (PGA)
B
What is the role of NADPH in photosynthesis? A. It supplies ADP with the energy and phosphate needed to produce ATP. B. It carries high energy electrons for a reduction reaction. C. It takes part in Photosystem II. D. It fuels the reaction that reconstitutes RuBP.
B
Plants containing only chlorophyll b are exposed to radiation with the following wavelengths: 10nm (x-rays), 450nm (blue light), 670nm (red light), and 800nm (infrared light). Which plants harness the most energy for photosynthesis?
Blue light irradiated plants
"Cytokinesis" refers to _____. A. division of the entire cell B. division of the nucleus C. division of the cytoplasm D. reduction in the number of chromosomes E. movement of a cell from one place to another
C
A G protein is active when _____. A. GDP replaces GTP B. it is bound by its ligand and transported to the nucleus C. GTP is bound to it D. it is phosphorylated by protein kinase E. Ca2+ binds to a G-protein-linked receptor
C
At which stage of meiosis are sister chromatids separated from each other? A. anaphase I B. prophase II C. anaphase II D. prophase I
C
Briefly describe the events that occur in each phase of interphase. A. G1 - preparation for DNA synthesis, S - assessment of DNA damage, M - Division of cell B. G1- duplication of organelles, S - duplication of DNA, G2 - assessment of DNA damage C. G1 - assessment for DNA damage, S - duplication of genetic material, G2 - duplication and dismantling organelles D. G1 - synthesis of DNA, S - synthesis of organelle genetic material, G2 - assessment of DNA damage
C
C4 plants differ from C3 and CAM plants in that C4 plants _____. A. open their stomata only at night B. are better adapted to wet conditions C. fix CO2 in mesophyll cell and supply it to bundle sheath cell where Calvin cycle occurs. D. are cactus with fleshy leaves. E. bypass the C3 pathway completely.
C
Chromosomes first become visible during ________ of mitosis. A. prometaphase B. telophase C. prophase D. metaphase E. anaphase
C
DNA is replicated at this time of the cell cycle. A. G0 B. G1 C. S D. G2 E. M
C
DNA replication occurs in _____. A. prophase of both mitosis and meiosis B. metaphase of meiosis only C. the S phase of interphase in both somatic and reproductive cells D. the G1 phase of interphase in reproductive cells only E. the cytokinesis portion of the cell's life cycle
C
Generation of proton gradients across membranes occurs in ________ A. photosynthesis B. respiration C. both, photosynthesis and respiration D. neither photosynthesis nor respiration
C
How would you explain why organisms that are capable of reproducing either asexually or sexually would prefer to reproduce sexually? A. Organisms would have the greatest reproductive success if they always reproduced sexually. B. Reproducing sexually is a genetic abnormality for organisms that normally reproduce asexually and is never preferred. C. Producing genetically variable offspring could increase the reproductive success during stressful environmental conditions. D. Producing genetically identical offspring through sexual reproduction would always increase the chance of survival for an organism.
C
In animal cell mitosis, the cleavage furrow forms during _____. A.anaphase B.G1 phase C.cytokinesis D.metaphase E.prophase
C
In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from A. the stroma to the photosystem II. B. the matrix to the stroma. C. the stroma to the thylakoid space. D. the intermembrane space to the matrix. E. ATP synthase to NADP+ reductase.
C
In thylakoids protons travel through ATP synthase to generate ATP. The catalytic "knobs" of ATP synthase are located _______ A. on the ATP molecules themselves. B. built into the center of the thylkoid stack (granum). C. on the stroma side of the membrane. D. on the pigment molecules of PSI and PSII. E. on the side facing the thylakoid space.
C
List some reasons why a cell that has just completed cytokinesis might enter the G0 phase instead of the G1 phase. A. Suspected DNA damage can lead the cell to undergo the G0 phase. B. Some cells are physiologically inhibited from undergoing any division and remain in the G0 phase to provide assistance to their neighboring cells C. Some cells reproduce only under certain conditions and, until then, they remain in the G0 phase. D. The lack of important components of cell division makes cells stay in the G0 phase.
C
Mitosis in a eukaryotic cell includes these steps, in order A. Metaphase, Prometaphase, Anaphase Telophase, Prophase B. Prophase, Metaphase, Prometaphase, Anaphase, Telophase C. Prophase, Prometaphase, Metaphase, Anaphase, Telophase D. Anaphase, Metaphase, Prometaphase, Prophase, Telophase E. Anaphase, Prometaphase, Metaphase, Prophase, Telophase
C
Plants that fix CO2 into organic acids at night when the stomata are open and carry out the Calvin cycle during the day when the stomata are closed are called A. C3 plants. B. C4 plants. C. CAM plants. D. C4 plants and CAM plants. E. C3 plants, C4 plants, and CAM plants.
C
The function of cellular respiration is to _____. A.reduce CO2 B.extract CO2 from the atmosphere C.extract usable energy from glucose D.synthesize macromolecules from monomers E.produce carbohydrates
C
Three of the same species of plant are each grown under a different colored light for the same amount of time. Plant A is grown under blue light, Plant B is grown under green light, and Plant C is grown under orange light. Assuming the plants use only chlorophyll a and chlorophyll b for photosynthesis, what would be the predicted order of the plants from most growth to least growth? A. B, A, C B. A, B, C C. A, C, B D. C, A, B
C
What are the products of noncyclic photophosphorylation? A. heat and fluorescence B. ATP and P700 C. ATP and NADPH D. ADP and NADP E. P700 and P680
C
What is a haploid cell produced in a diploid-dominant organism by meiosis called? A. sporophyte B. gametophyte C. gamete D. spore
C
What is a reason why there are fewer offspring from a population that reproduces sexually than from a population that reproduces asexually? A. Asexual organisms are more fit for their environment. B. Sexually reproducing organisms don't live as long. C. Sexually reproducing organisms expend energy seeking and attracting mates. D. The offspring have more genetic variations.
C
What is a reason why there are fewer offspring from a population that reproduces sexually than from a population that reproduces asexually? A. Sexually reproducing organisms don't live as long. B. The offspring have more genetic variations. C. Sexually reproducing organisms expend energy seeking and attracting mates. D. Asexual organisms are more fit for their environment.
C
What would be the outcome of blocking S-phase of interphase? A. The cell would enter karyokinesis. B. Centrosomes would be duplicated. C. DNA replication would not occur. D. The cytoskeleton would be dismantled.
C
When chloroplast pigments absorb light, _____. A.they become reduced B.they lose potential energy C.their electrons become excited D.the Calvin cycle is triggered E.their photons become excited
C
When oxygen is released as a result of photosynthesis, it is a by-product of which of the following? A. the electron transfer system of photosystem I B. reducing NADP+ C. splitting the water molecules D. chemiosmosis E. the electron transfer system of photosystem II
C
Which one of the following processes does not occur in dividing bacteria? A. replication of DNA B. separation of the origins of replication C. mitosis D. binary fission E. inward growth of the plasma membrane
C
Which phase of a fern's life cycle is free living? A. neither diploid nor haploid phase B. only the sporophyte C. both diploid and haploid phases D. only the gametophyte
C
What would be the outcome if ubiquinone in the electron transport chain was blocked and could not function?
Complex III would not receive electrons.
A clone is the product of _____. A. asexual reproduction B. sexual reproduction C. mitosis D. A and C are correct E. A and B are correct
D
A human cell containing 22 autosomes and a Y chromosome is A. a somatic cell of a male. B. a zygote. C. a somatic cell of a female. D. a sperm cell. E. an ovum.
D
All of the following occur during prophase of mitosis in animal cells except A. the centrioles move toward opposite poles. B. the nucleolus can no longer be seen. C. the nuclear envelope disappears. D. DNA duplication occurs. E. the spindle is organized.
D
Drosophila melanogaster (fruit fly) has 4 pairs of chromosomes (2n=8) in its somatic cells. How many different types of gametes are possible due to independent assortment? A. 2 B. 4 C. 8 D. 16
D
Examine the phosphorylation cascade. What are possible advantages of such a long, multistep process? A. Complexity helps regulate the mechanism at multiple steps. B. There is no advantage to a complex cascade. It is a vestigial pathway. C. The benefit is amplification of the signal. D. Benefits include amplification of the signal and multiple check points.
D
Explain how the light reactions and light independent reactions (Calvin cycle) of photosynthesis are interdependent on each other. A. The light reactions uses NADPH and ATP, which are produced by the Calvin cycle. B. The light reactions produce only NADPH, which is produced by the Calvin cycle. C. The light reactions produces NADP+ and ADP, which are then used in the Calvin cycle. D. The light reactions produces ATP and NADPH, which are then used in the Calvin cycle.
D
How does carbon dioxide enter the leaf? A. through the chloroplasts B. through the mesophyll C. through the thylakoids D. through the stomata E. through the vascular system
D
How does the alignment of chromosomes during prophase I facilitate the crossing over of chromosomal material? A. The synaptonemal complex forms bridges between the paired homologous chromosomes at points where crossing over occurs. B. The homologous chromosomes cross over at recombination nodules, where the chromatids physically overlap. C. The chiasmata holds the homologous chromosomes closely together at a few specific points along their lengths. D. The homologous chromosomes are tightly paired along their entire lengths, forming a synapsis.
D
How many ATP are generated by the enzymes that convert pyruvate to lactate? A. 2 B. 10 C. 6 D. 0
D
Of the metabolic pathways listed below, which is the only pathway found in all organisms? A. cellular respiration B. the citric acid cycle C. the electron transport chain D. glycolysis E. fermentation
D
One carbon dioxide molecule reacts in each "turn" of the Calvin cycle. How many turns of the cycle are required for the synthesis of one glucose molecule? A. 1 B. 2 C. 3 D. 6 E. 12
D
The net gain of ATP from glycolysis (of 1 glucose) is compared to the ATP produced in cellular respiration: therefore, cellular respiration is a more efficient use of glucose in the cell. A. 2:6 B. 4:32 C. 36:4 D. 2:32
D
What is a reason why there are fewer offspring from a population that reproduces sexually than from a population that reproduces asexually? A. Sexually reproducing organisms don't live as long. B. Asexual organisms are more fit for their environment. C. The offspring have more genetic variations. D. Sexually reproducing organisms expend energy seeking and attracting mates.
D
What is a reason why there are fewer offspring from a population that reproduces sexually than from a population that reproduces asexually? A. The offspring have more genetic variations. B. Asexual organisms are more fit for their environment. C. Sexually reproducing organisms don't live as long. D. Sexually reproducing organisms expend energy seeking and attracting mates.
D
When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the A. formation of ATP. B. reduction of NAD+. C. restoration of the Na+/K+ balance across the membrane. D. creation of a proton gradient. E. lowering of pH in the mitochondrial matrix.
D
When illuminated with light of desired wavelength, electrons from special pair of chlorophyll in the reaction center complex are excited. The excited electrons reduce the primary electron acceptors causing the oxidation of the special pair chlorophyll molecules. How does the special chlorophyll pair restore their lost electrons? A. The P700+ is reduced by splitting water; P680+ by electrons from Photosystem I. B. The P680+ is reduced by splitting water; P700+ by electrons form NADPH C. The P680+ is reduced by splitting water; P700+ by electrons from ATP. D. The P700+ is reduced by electrons from Plastocyanin (PC); P680+ by electrons from splitting of water. E. Neither P680+ nor P700+ because both are already reduced special pair.
D
Where is ATP synthase located in the mitochondrion? A. cytosol B. electron transport chain C. outer membrane D. inner membrane E. nucleus
D
Which molecule must enter the Calvin cycle continually for the light-independent reactions to take place? A. 3-PGA B. RuBP C. RuBisCO D. CO2
D
Which of the following statements about cell signaling is correct A. An autocrine signal is a long-distance signal that is delivered by hormones traveling through an organism's circulatory system from the signaling cell to the target cell. B. A paracrine signal is a signal that is sent and received by the same cell. C. An endocrine signal is a signal between nearby cells that is delivered by ligands traveling in the liquid medium in the space between the cells. D. A gap junction signal is a signal that is delivered by intracellular mediators between the plasma membranes of neighbouring cells.
D
Which of the following stores energy released from chemiosmosis? A. NADH B. electron transport C. FADH2 D. ATP synthase E. cytochromes
D
Which one of the following does not occur during, or because of, mitosis? A. the production of two genetically identical daughter cells B. condensed chromatin C. separation of chromatids D. replication of chromosomes E. alignment of chromosomes along the cell's equator
D
Centrioles begin to move apart at ________ in animal cells. A. telophase B. anaphase C. prometaphase D. metaphase E. prophase
E
Centromeres divide and sister chromatids become full-fledged chromosomes during _____. A. metaphase B. interphase C. prometaphase D. telophase E. anaphase
E
Consider this pathway: epinephrine → G protein-coupled receptor → G protein → adenylyl cyclase → cAMP. Identify the second messenger. A. GTP B. adenylyl cyclase C. G protein D. G protein-coupled receptor E. cAMP
E
During aerobic respiration, molecular oxygen (O2) is used for which of the following purposes? A. at the end of glycolysis to oxidize pyruvate B. at the end of the citric acid cycle to regenerate citric acid C. between glycolysis and the citric acid cycle to split a carbon from pyruvate, producing CO2 D. as a source of O2 in every reaction that produces CO2 E. at the end of the electron transport chain to accept electrons and form H2O
E
During which phases of mitosis are chromosomes composed of two chromatids? A. from interphase through anaphase B. from G1 of interphase through metaphase C. from metaphase through telophase D. from anaphase through telophase E. from G2 of interphase through metaphase
E
If a cell has 8 chromosomes at metaphase of mitosis, how many chromosomes will it have during anaphase? A.1 B.2 C.4 D.8 E.16
E
In a cell in which 2n = 6, the independent assortment of chromosomes during meiosis can by itself give rise to ________ genetically different gametes. A. two B. four C. five D. six E. eight
E
In chloroplasts, chemiosmosis translocates protons from ______ A. the stroma to the photosystem II. B. the matrix to the stroma. C. the stroma to the thylakoid space. D. the intermembrane space to the matrix. E. the thylakoid space to the stroma.
E
Muscle tissues make lactic acid from pyruvic acid in order to do which of the following? A. speed up the rate of glycolysis B. get rid of pyruvate produced by glycolysis C. utilize the energy in pyruvate D. produce additional CO2 E. regenerate NAD+
E
Pyruvate is formed A. on the inner mitochondrial membrane. B. in the mitochondrial matrix. C. on the outer mitochondrial membrane. D. in the nucleus. E. in the cytosol.
E
Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed during glycolysis? A. 0% B. 2% C. 10% D. 38% E. 100%
E
What is a karyotype? A.the set of unique physical characteristics that define an individual B.the collection of all the mutations present within a genome C.a unique combination of chromosomes found in a gamete D.a system of classifying cell nuclei E.a display of every pair of homologous chromosomes within a cell, organized according to size and shape
E
When yeast cells break down glucose anaerobically, they produce A. Lactic acid B. Acetyl-CoA C. FADH2 D. RuBP E. Ethanol + CO2
E
Where do the electrons needed by photosystem II originate? A. other chlorophyll molecules B. ATP C. the electron transport chain D. light E. water
E
Which are products of the light reactions of photosynthesis that are used in the Calvin cycle? A. CO2 and glucose B. H2O and O2 C. ADP, Pi, and NADP+ D. electrons and H+ E. ATP and NADPH
E
Which does not occur during anaphase of mitosis? A. The centromeres divide. B. Centrioles are at opposite poles. C. Spindle made of microtubules is present. D. Identical chromatids move to opposite poles. E. Nuclear membrane forms.
E
Which of the following produces the most ATP when glucose (C6H12 O6) is completely oxidized to carbon dioxide (CO2) and water? A. glycolysis B. fermentation C. oxidation of pyruvate to acetyl CoA D. citric acid cycle E. oxidative phosphorylation (chemiosmosis)
E
Which of these acts as a second messenger? A. G protein B. G-protein-linked receptor C. protein kinase D. adenylyl kinase E. cyclic AMP
E
Which process is most directly driven by light energy? A. reduction of NADP+ molecules B. ATP synthesis C. carbon fixation in the stroma D. creation of a pH gradient by pumping protons across the thylakoid membrane E. removal of electrons from chlorophyll molecules
E
cAMP usually directly activates _____. A. phosphodiesterase B. receptor tyrosine kinases C. G proteins D. adenylyl cyclase E. protein kinase A
E
Homologous chromosomes synapse (zip) forming tetrads in mitosis. True False
False
Explain how haploid and diploid cells differ from each other. State which cells in the human body are diploid and which are haploid.
Haploid cells only have one copy of each chromosomes. Diploid cells have double that number and form sets of two. Somatic cells are diploid cells and gametes are haploid cells.
Explain how independent assortment, crossing over, and random fertilization contribute to genetic variation in sexually reproducing organisms. Please be specific and include a description of what these terms mean.
Independent assortment, crossing over, and random fertilization contribute to genetic variation by increasing the diversity of offspring. Independent assortment is the number of possible variations that an organism could conceive depending on the number of chromosomes; crossing over is when two homologous chromosomes (one paternal and the other maternal; they are different by who they came from but are similar in their functions) trade segments of DNA, which further increases the diversity of the offspring; random fertilization is based on all the variations of offspring that were to occur for more different partners (fertilization can be between one female and one male, and that female or male may go with another male or female which further increases the diversity of offspring.) For humans, for example, there are about 70 trillion possible variations of offspring per one couple, and that is regarding only independent assortment and crossing over of the chromosomes. With random fertilization, the variations do not necessarily increase but it changes as one partner goes with another partner (it is different and just as diverse as with the initial couple.)
he combustion of glucose occurs as an oxidation-reduction reaction according to the chemical equation: C6H12O6(s)+6O2(g)→6CO2(g)+6H2O(g)C6H12O6(s)+6O2(g)→6CO2(g)+6H2O(g) Which component of the equation is reduced during the reaction?
O2
List four phases of mitosis. Describe the events characteristics of prophase and metaphase.
Prophase, Metaphase, Anaphase, Telophase During prophase, the parent cell chromosomes that are duplicated during S phase condense and become thousands of times more compact than they were in interphase. They chromosomes are seen as an X shape under microscope. Cohesin forms rings that hold sister chromatids together whereas condensing forms rings that coil that chromosomes into highly compact forms. Also, the mitotic spindle begins to develop. (Nuclear envelope and nucleolus dissapear. Organelles move to periphery. Centrioles move to sides by microtubules. Condensin proteins coil the sister chromatids tighter) During Metaphase, the cell's chromosomes align themselves in the middle of the cell at a thing called the metaphase plate. This is where duplicated genetic material in the nucleus of the parent cell separates into two identical daughter cells.
The world's most abundant protein is an enzyme found in chloroplast. It can build sugar or break it down by photorespiration. This enzyme is called ___________________.
RUBISCO|Ribulose bisphosphate carboxylase oxygenase
What is the cell cycle? Explain the role of cyclin and cyclin dependent kinase in the regulation of cell division.
The cell cycle is "an ordered series of events involving cell growth and cell division that produces two new daughter cells" (Interphase - G1, S, G2, is cell growth; karyokinesis is cell division). Both cyclin and cyclin-dependent kinase (Cdk) (proteins) are positive regulators that help to regulate the cell cycle (that is, they promote progress of the cell to move onto the next phase in the cell cycle, wheras for negative regulators they promote "pause", meaning they halt the cell cycle). There are four cyclin proteins in which the levels of each fluctuate throughout various stages in the cell cycle. An increase in the level of cyclin proteins are triggered by internal and/or external signals. The cyclins can regulate the cell cycle only if they are tightly bound Cdks. In order for the cyclin/Cdk complex to be activated, it must be phosphorylated (to add a phosphate group to a molecule), and the Cdk of the complex can phosphorylate other proteins. The proteins that the Cdk phosphorylates are involved in progressing the cell into the next phase in the cell cycle. Cyclins cannot work alone in regulating the cell cycle, but Cdks can do either (work alone or work with cyclins). *negative regulators - promote "PAUSE" (abruption or halting of something) ("nerpa") *positive regulators - promote PROGRESS ("propro" or "porpro"?)
CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they A. fix CO2 into organic acids during the night. B. fix CO2 into sugars in the bundle-sheath cells. C. fix CO2 into pyruvate in the mesophyll cells. D. use the enzyme phosphofructokinase, which outcompetes rubisco for CO2 . E. use photosystems I and II at night.
a
Carbon, in the form of CO2, must be taken from the atmosphere and attached to an existing organic molecule in the Calvin cycle. Therefore, the carbon is bound to the molecule. The products of the cycle only occur because of the added carbon. What are the products of the Calvin cycle and what is regenerated? a. The product of the Calvin cycle is glyceraldehyde-3 phosphate and RuBP is regenerated. b. The product of the Calvin cycle is glyceraldehyde-3 phosphate and RuBisCO is regenerated. c. The product of the Calvin cycle is a 3-PGA molecule and glyceraldehyde-3 phosphate is regenerated. d. The product of the Calvin cycle is glyceraldehyde-3 phosphate and oxygen is regenerated.
a
Cellular respiration breaks down glucose and releases carbon dioxide and water. Which steps in the oxidation of pyruvate produces carbon dioxide? a. Removal of a carboxyl group from pyruvate releases carbon dioxide. The pyruvate dehydrogenase complex comes into play. b. Removal of an acetyl group from pyruvate releases carbon dioxide. The pyruvate decarboxylase complex comes into play. c. Removal of a carbonyl group from pyruvate releases carbon dioxide. The pyruvate dehydrogenase complex comes into play. d. Removal of an acetyl group from pyruvate releases carbon dioxide. The pyruvate dehydrogenase complex comes into play.
a
Common medications called β-blockers bind to G-protein-linked receptors in heart muscles, blocking adrenaline. They are prescribed to patients with high blood pressure. Can you formulate a hypothesis on their mechanism of action? a. Adrenaline has a stimulatory effect on heart rate and blood pressure. β-blockers are antagonistic to adrenaline and produces inhibitory effect. b. Adrenaline has both a stimulatory and an inhibitory effect on heart rate and blood pressure. β-blockers bind to G-protein and stimulate the inhibitory effect of adrenaline. c. Adrenaline has an inhibitory effect on heart rate and blood pressure. β-blockers have a synergistic effect along with adrenaline producing an inhibitory effect. d. Adrenaline has both a stimulatory and an inhibitory effect on heart rate and blood pressure. β-blockers bind to G-protein and intervene with the inhibitory effect of adrenaline.
a
Dinitrophenol (DNP) is an uncoupler that makes the inner mitochondrial membrane leak protons (H+)(H+). It was used until 1938 as a weight-loss drug. Why do you think this might be an effective weight-loss drug? a. DNP dissipates the proton gradient in the matrix, preventing the production of ATP. The body then increases its metabolic rate, leading to weight loss. b. DNP decreases the proton gradient in the inner mitochondrial space, leading to rapid consumption of acetyl-CoA, which causes weight loss. c. DNP blocks the movement of protons through the ATP synthase, halting ATP production. The stored energy dissipates as heat, causing weight loss. d. DNP uncouples the production of ATP by increasing the proton gradient in the matrix. The stored energy dissipates as heat, causing weight loss.
a
Explain how the light reactions and light independent reactions (Calvin cycle) of photosynthesis are interdependent on each other. a. The light reactions produces ATP and NADPH, which are then used in the Calvin cycle. b. The light reactions produces NADP+ and ADP, which are then used in the Calvin cycle. c. The light reactions uses NADPH and ATP, which are produced by the Calvin cycle. d. The light reactions produce only NADPH, which is produced by the Calvin cycle.
a
Formulate a few advantages of having autocrine signals in the body and justify your answers with examples. a. Autocrine signaling helps to amplify the signal. b. Autocrine signaling helps to connect distantly located cells c. Autocrine signaling coordinates the response of nearby different cells. d. Autocrine signaling influences the differentiation of nearby cells into different types of cells.
a
If the pH outside the cell decreases, would you expect the amount of amino acids transported into the cell to increase or decrease? a. Transport of amino acids into the cell increases b. Transport of amino acids into the cell stops. c. Transport of amino acids into the cell is not affected by pH. d. Transport of amino acid into the cell decreases.
a
In which phase of the mitotic cell can nondisjunction occur? a. anaphase b. metaphase c. prophase d. telophase
a
Is the citric acid cycle considered an aerobic or an anaerobic pathway? Why? a. The citric acid cycle is considered an aerobic pathway because it's products must donate their electrons to the electron transport chain, which relies on oxygen. b. It is anaerobic, as it does not use oxygen directly. Even if oxygen is absent, the citric acid cycle would still work. c. It is aerobic, as it uses the water produced in the process of respiration. This water is produced when oxygen accepts electrons. d. It is anaerobic, as it is a part of the fermentation process which does not require oxygen as a final electron acceptor.
a
Nearly all organisms on earth carry out some form of glycolysis. How does this fact support or not support the assertion that glycolysis is one of the oldest metabolic pathways? a. To be present in so many different organisms, glycolysis was probably present in a common ancestor rather than evolving many separate times. b. Glycolysis is present in nearly all organisms because it is an advanced and recently evolved pathway that has been widely used as it is so beneficial. c. Glycolysis is absent in a few higher organisms. This contradicts the fact that it is one of the oldest metabolic pathways. d. Glycolysis is present in some organisms and absent in others. The mentioned fact may or may not support this assertion.
a
Rb and other proteins that negatively regulate the cell cycle are sometimes called tumor supressors. Why do you think the name tumor suppressor might be appropriate for these proteins? a. They inhibit cell division. b. They enhance the rate of cell division. c. They start the cell cycle, thereby suppressing tumor formation. d. These proteins, when phosphorylated, allow the cell cycle to proceed.
a
The ______ plants have a spatial separation for photosynthesis whereas the _______ plants have a temporal separation for photosynthesis. A. C4:CAM B. C3: CAM C. CAM: C4 D. CAM: C3 E. None of the above
a
The secretion of a hormone by the pituitary gland that targets cells in the kidney is an example of______. A.endocrine signaling B.paracrine signaling C.direct signaling across gap junctions D.autocrine signaling
a
Treating cancer can be described as a fight against natural biologic processes. Explain what this means in terms of tumor formation. a. Cancer forms when natural defenses are inhibited and cells divide uncontrollably. b. Mutated cells undergo apoptosis, causing cells to divide uncontrollably. c. Cancer treatment would require inhibiting apoptosis which is a natural defense. d. In cancerous cells, apoptosis occurs.
a
Tremetol, a metabolic poison found in the white snake root plant, prevents the metabolism of lactate. When cows eat this plant, it is concentrated in the milk they produce. Humans who consume the milk become ill. Symptoms of this disease, which include vomiting, abdominal pain, and tremors, become worse after exercise. Why do you think this is the case? a. Tremetol inhibits enzymes that convert lactate into less harmful compounds. Exercise worsens this by producing more lactate. b. Tremetol increases the production of lactate dehydrogenase, causing lactic acid to accumulate in the body. c. Tremetol inhibits the production of NAD+ after exercise. The lack of oxygen causes lactic acid to accumulate in the body. d. Tremetol binds to lactic acid, inhibiting its breakdown into other compounds and causing it to accumulate after exercising.
a
What are the roles of ATP and NADPH in photosynthesis? a. ATP and NADPH are forms of chemical energy produced from the light dependent reactions to be used in the light independent reactions that produce sugars. b. ATP and NADPH are forms of chemical energy produced from the light independent reactions, to be used in the light dependent reactions that produce sugars. c. ATP and NADPH are forms of chemical energy produced from the light dependent reactions to be used in the light independent reactions that produce proteins. d. ATP and NADPH are forms of chemical energy produced from the light dependent reactions to be used in the light independent reactions that use sugars as reactants.
a
What evidence exists that the evolution of photosynthesis and cellular respiration support the concept that there is a common ancestry for all organisms? a. All organisms perform cellular respiration, using oxygen and glucose, which are produced by photosynthesis. b. All organisms perform cellular respiration using carbon dioxide and glucose, which are produced by photosynthesis. c. All organisms perform cellular respiration using oxygen and lipids, which are produced by photosynthesis. d. All organisms perform cellular respiration using carbon dioxide and lipids, which are produced by photosynthesis.
a
What evidence provides the strongest support that glycolysis is an older and more conserved pathway than the citric acid cycle? a. Glycolysis is the primitive pathway as it is found in all three domains. It also occurs in anaerobic conditions and in the cytosol. b. This pathway occurs in the cytosol, is found in all animals and plants, and does not require oxygen. c. Glycolysis takes place in anaerobic conditions, can metabolize cholesterol and fatty acids, and occurs even in methanogens. d. This pathway only occurs in the mitochondria. It is highly flexible because it is found in almost all organisms.
a
What is the carbon cycle? a. The fixing of carbon from inorganic to organic form for utilization in energy pathways and converting it back to inorganic form after the completion of these pathways. b. The fixing of carbon from organic form to inorganic form for utilization in energy pathways and converting it back to organic form after the completion of these pathways. c. The fixing of carbon from inorganic to organic form for utilization in energy pathways and returning it back in organic form after the completion of these pathways. d. The fixing of carbon from organic to inorganic form for utilization in energy pathways and returning it back in inorganic form after the completion of these pathways.
a
What is the general formula for cellular respiration and what roles do oxygen and carbon dioxide play in this process? a. C6H12O6+O2→CO2+H2O+energyC6H12O6+O2→CO2+H2O+energy, where glucose is oxidized to release carbon dioxide along with energy and oxygen is the final acceptor of electrons. b. C6H12O6+CO2→O2+H2O+energyC6H12O6+CO2→O2+H2O+energy, where glucose is reduced to release oxygen and water. This oxygen in turn accepts electrons from the electron transport chain to form water. c. C6H12O6+O2+H2O→CO2+C6H12O6+O2+H2O→CO2+ energy, where glucose is reduced to release carbon dioxide with energy. Oxygen works as a reducing agent by donating electrons. d. C6H12O6+CO2→(CH2O) n+H2O+O2C6H12O6+CO2→(CH2O) n+H2O+O2 where glucose is oxidized to release pyruvate and water. The oxygen formed acts as the final acceptor of electrons.
a
What is the overall outcome of the light reactions in photosynthesis? a. NADPH and ATP molecules are produced during the light reactions and are used to power the light independent reactions. b. NADPH and ATP molecules are produced during the light reactions, which are used to power the light dependent reactions. c. Sugar and ATP are produced during the light reactions, which are used to power the light independent reactions. d. Carbon dioxide and NADPH are produced during the light reactions, which are used to power the light dependent reactions.
a
What is the primary difference between a circular pathway and a linear pathway? a. The reactant and the product are the same in a circular pathway but different in a linear pathway. b. The circular pathway components get exhausted whereas those of the linear pathway do not and are continually regenerated. c. Circular pathways are not suited for amphibolic pathways whereas linear pathways are. d. Circular pathways contain a single chemical reaction that is repeated while linear pathways have multiple events.
a
What is the primary difference between fermentation and anaerobic respiration? a. Fermentation uses only glycolysis and its final electron acceptor is an organic molecule, whereas anaerobic respiration uses glycolysis, TCA and the ETC but finally give electrons to an inorganic molecule. b. Fermentation uses glycolysis, TCA and ETC but finally gives electrons to an inorganic molecule, whereas anaerobic respiration uses only glycolysis and its final electron acceptor is an organic molecule. c. Fermentation uses glycolysis and its final electron acceptor is an inorganic molecule, whereas anaerobic respiration uses glycolysis, TCA and ETC but finally give electrons to an organic molecule. d. Fermentation uses glycolysis, TCA and ETC but finally gives electrons to an organic molecule, whereas anaerobic respiration uses only glycolysis and its final electron acceptor is an inorganic molecule.
a
What role does NAD+NAD+ play in redox reactions? a. NAD+NAD+, an oxidizing agent, can accept electrons and protons from organic molecules and get reduced to NADHNADH. b. NAD+NAD+, a reducing agent, can donate its electrons and protons to organic molecules. c. NAD+NAD+, an oxidizing agent, can accept electrons from organic molecules and get reduced to NADH2. d. NAD+NAD+, a reducing agent, can donate its electrons and protons to inorganic molecules.
a
What would happen if the intracellular domain of a cell-surface receptor was switched with the domain from another receptor? a. It would activate the pathway normally triggered by the receptor that contributed the intracellular domain. b. It would activate the same pathway even after the intracellular domain is changed with the domain from another receptor. c. The receptor will be mutated and become non-functional, not activating any pathway. d. The receptor will become mutated and lead to continuous cell signaling, even in the absence of a ligand.
a
Where is the electron transport chain found in plant cells? A. thylakoid membranes of chloroplasts B. stroma of chloroplasts C. inner membrane of mitochondria D. matrix of mitochondria E. cytoplasm
a
Which of the following statements about glycolysis is true? A. Glycolysis is anaerobic. B. Glycolysis takes place only in eukaryotes. C. The first half of glycolysis extracts energy and stores it in the form of ATP and NADH. D. Glycolysis ends with the production of 3 molecules of pyruvate.
a
Which organism employs a diploid-dominant life-cycle strategy? A. a gorilla B. a red alga C. an evergreen tree D. a mushroom
a
Which structure contains the thylakoid membrane in a chloroplast? a. granum b. stroma c. cristae d. There is no such membrane in a chloroplast.
a
Why are anabolic and catabolic chemical reactions dependent on each other in a metabolic pathway? a. Anabolic reaction utilizes the energy released by the catabolic reactions to form complex compounds. b. Catabolic reaction utilizes the energy released by the anabolic reactions to form complex compounds. c. Anabolic reaction gives energy which is utilized by the catabolic reactions to increase the rate of reaction. d. Anabolic reaction utilizes the reactants of the catabolic reactions to form complex compounds.
a
Why is it possible for humans to digest food that contains starch, but not cellulose? a. Amylase can digest 1,4 linkage of glucose found in starch whereas it cannot digest the linkage of glucose found in cellulose. b. Amylase can digest 1,4 linkage of glucose found in cellulose whereas it can't digest the glucose found in starch. c. Amylase can digest the 1,4 linkage of glucose molecules found in starch but not the glucose found in cellulose. d. Amylase can digest the 1,6 linkage of glucose found in starch whereas it cannot digest the 1,6 linkage of glucose found in cellulose.
a
Why is nucleosome formation required for the packaging of DNA? a. Nucleosome formation results in compaction of the DNA to form chromatin. b. Nucleosome formation results in DNA synthesis. c. Nucleosome formation decreases the number of introns in DNA. d. Nucleosome formation increases the number of introns in the DNA.
a
Why is signaling in multicellular organisms more complicated than signaling in single-celled organisms? a. Multicellular organisms coordinate between distantly located cells; single-celled organisms communicate only with nearby cells. b. Multicellular organisms involve receptors for signaling; single-celled organisms communicate by fusion of plasma membrane with the nearby cells. c. Multicellular organisms require more time for signal transduction than single-celled organisms, as they show compartmentalization. d. Multicellular organisms require more time for signal transduction than single-celled organisms, as they lack compartmentalization.
a
A cell entering the cell cycle with 2n=32 chromosomes produces two daughter cells, each with _____. A. 16 chromosomes B. 32 chromosomes C. 32 pairs of chromosomes D. 64 pairs of chromosomes
b
A scientist observes a mutation in the transmembrane region of EGFR that eliminates its ability to be stabilized by binding interactions during dimerization after ligand binding. Which hypothesis regarding the effect of this mutation on EGF signaling is most likely to be correct? a. EGF signaling cascades would be active for longer in the cell. b. EGF signaling cascades would be active for a shorter period of time in the cell. c. EGF signaling cascades would not occur. d. EGF signaling would be unaffected.
b
At which stage of mitosis are chromosomes lined up in one plane in preparation for their separation to opposite poles of the cell? A. prophase B. metaphase C. anaphase D. telophase E. interphase
b
At which stage of mitosis are chromosomes photographed in the preparation of a karyotype? A. prophase B. metaphase C. anaphase D. telophase E. interphase
b
Cells will usually divide if they receive the proper signal at a checkpoint in the _____ phase of the cell cycle. A. M B. G1 C. S D. G2 E. cytokinesis
b
Chromosomes become visible during _____. A. metaphase B. prophase C. interphase D. prometaphase E. anaphase
b
Explain how a chemical that blocks the binding of EGF to the EGFR would interfere with the replication of cancerous cells that overexpress EGFR. a. It will activate the EGFR pathway. b. It will block the EGFR pathway. c. It will have no effect and the EGFR pathway will continue normally d. It will lead to overexpression of the EGFR pathway
b
How do desert plants prevent water loss from the heat, which would compromise photosynthesis? a. by using CAM photosynthesis and by closing stomatal pores during the night b. by using CAM photosynthesis and by opening of stomatal pores during the night c. by using CAM photosynthesis and by keeping stomatal pores closed at all times d. by bypassing CAM photosynthesis and by keeping stomatal pores closed at night
b
In autoimmune lymphoproliferative syndrome (ALPS), lymphocytes which multiplied during an infection persist in the body and damage tissue. The syndrome is caused by a mutation in the FAS gene which encodes a cell surface receptor. Which signaling pathway does the receptor initiate? a. activated metabolism b. apoptosis c. cell division d. cell differentiation
b
In eukaryotic cells, which one of the following is a second messenger that is produced as a response to an external signal such as a hormone? A. glycogen B. cyclic AMP C. tRNA D. epinephrine E. glucose
b
In eukaryotic cells, which one of the following is a second messenger that is produced as a response to an external signal such as a hormone? A. glycogen B. cyclic AMP C. tRNA D. epinephrine E. glucose
b
In photosynthesis, plants use carbon from _____ to make sugar and other organic molecules. A. water B. carbon dioxide C. chlorophyll D. the sun E. soil
b
Most of the ATP produced in cellular respiration comes from which of the following processes? A. glycolysis B. oxidative phosphorylation C. reduction of NADH D. substrate-level phosphorylation E. the citric acid cycle
b
The combustion of glucose occurs as an oxidation-reduction reaction according to the chemical equation: C6H12O6(s)+6O2(g)→6CO2(g)+6H2O(g)C6H12O6(s)+6O2(g)→6CO2(g)+6H2O(g) Which component of the equation is reduced during the reaction? a. C6H12O6 b. O2 c. CO2 d. H2O
b
The somatic cells derived from a single-celled zygote divide by which process? a. meiosis b. mitosis c. replication d. cytokinesis alone e. binary fission
b
Thiomargarita namibiensis is a large single cell organism, which can reach lengths of 700μm700μm. The cell is classified as a bacterium. What is the main argument to justify the classification? a. This organism shows simple diffusion for the uptake of nutrients and is thus classified as a bacterium. b. This organism does not show presence of any cell organelles, and thus is classified as a bacterium. c. the existence of these organisms in long chains and pearl appearance d. The organism demonstrates characteristics of gram-negative bacteria, and thus is classified as a bacterium.
b
Upon ingestion of bacteria, white blood cells release a chemical messenger into the blood stream that causes the synthesis of inflammation response proteins by liver cells. What is this is an example of? a. autocrine signaling b. endocrine signaling c. paracrine signaling d. synaptic signaling
b
What is the name for the special region on a duplicated chromosome that holds the sister chromatids together? A. centrosome B. centromere C. kinetochore D. desmosome E. microtubule organizer region
b
Which best describes how ATP synthase makes ATP in the thylakoid membrane? A. ATP synthase facilitates energy in the form of ATP to be passed along from Photosystem II. This passage of energy produces the H+ gradient as the protons move through the ATP synthase B. ATP synthase provides passage for hydrogen protons (H+). As the H+ ions travel through the enzyme, ADP and Pi are combined to make ATP. C. ATP synthase passes electrons to the ADP molecule. This creates an ADP molecule that allows for the attachment of a Pi molecule, which creates ATP. D. ATP synthase helps catalyze the transfer of electrons from plastoquinol to plastocyanin.
b
Which of the following statements about quorum sensing is false? a. Autoinducers must bind to receptors to turn on transcription of genes responsible for the production of more autoinducers. b. Autoinducers can only act on a different cell. It cannot act on the cell in which it is made. c. Autoinducers turn on genes that enable the bacteria to form a biofilm. d. The receptor stays in the bacterial cell, but the autoinducers diffuse out.
b
Why is the mitochondria considered the powerhouse of the cell? a. Glycolysis takes place in mitochondria which extract energy by glucose breakdown for cellular metabolism. b. Most of the ATP is produced in mitochondria by oxidative phosphorylation. c. All the pathways involved in ATP production take place in the mitochondria. d. The outer membrane of mitochondria is loaded with proteins involved in electron transfer and ATP synthesis.
b
A single diploid cell with 22 chromosomes undergoes meiosis and produces gametes. Describe the cells produced. A. Meiosis cannot occur on a diploid cell. B. The result would be one cell with 22 chromosomes. C. The result would be four cells, each containing 11 chromosomes. D. The result would be four cells, each containing 22 chromosomes.
c
During _____ sister chromatids separate in meiosis. A. prophase I B. prophase II C. anaphase II D. interphase E. Anaphase I
c
Eukaryotic chromosomes are thousands of times longer than a typical cell. Explain how chromosomes can fit inside a eukaryotic nucleus. a. The genetic material remains distributed in the nucleus, mitochondria, and chloroplast. b. The genome is present in a looped structure, thus it fits the size of the nucleus. c. The DNA remains coiled around proteins to form nucleosomes. d. The genetic material remains bound to the nuclear envelope, forming invaginations.
c
Explain the roles of the positive cell cycle regulators compared to the negative regulators. a. Positive regulators promote the cell cycle but negative regulators block the cell cycle. b. Positive regulators block the cell division in cancerous cells but negative regulators promote in such cells. c. Positive regulators promote the cell cycle but negative regulators arrest the cell cycle until certain events have occurred. d. Positive regulators show positive feedback mechanisms but negative regulators show negative feedback in the cell cycle.
c
Explain why steroid hormones bind to intracellular receptors. a. Steroids are hydrophilic molecules. b. Steroids are both hydrophilic and hydrophobic. c. Steroids are lipophilic molecules. d. Steroids are amphipathic molecules.
c
Glucose catabolism pathways are sequential and lead to the production of ATP. What is the correct order of the pathways for the breakdown of a molecule of glucose as shown in the formula? C6H12O6+O2→CO2+H2O+energy a. oxidative phosphorylation →→ citric acid cycle →→ oxidation of pyruvate →→glycolysis b. the oxidation of pyruvate →→ citric acid cycle →→ glycolysis →→ oxidative phosphorylation c. glycolysis →→ oxidation of pyruvate →→ citric acid cycle →→ oxidative phosphorylation d. citric acid cycle →→ glycolysis →→ oxidative phosphorylation →→ oxidation of pyruvate
c
If four molecules of carbon dioxide enter the Calvin Cycle (four "turns" of the cycle), how many G3P molecules are produced and how many are exported? a. 4 G3P made, 1 G3P exported b. 4 G3P made, 2 G3P exported c. 8 G3P made, 1 G3P exported d. 8 G3P made, 4 G3P exported
c
In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from A. the stroma to the photosystem II. B. the matrix to the stroma. C. the stroma to the thylakoid space. D. the intermembrane space to the matrix. E. ATP synthase to NADP+ reductase.
c
Injection of a potassium solution into a person's blood is lethal. Potassium is used in capital punishment and euthanasia. Why do you think a potassium solution injection is lethal? a. Excess potassium disrupts the membrane components b. Excess potassium increases action potential generation, leading to uncoordinated organ activity. c. Potassium dissipates the electrochemical gradient in cardiac muscle cells, preventing them from contracting. d. Potassium creates a new concentration gradient across the cell membrane, preventing sodium from leaving the cell.
c
Thyroid hormone is a lipid-soluble signal molecule that crosses the membrane of all cells. Why would a cell fail to respond to the thyroid hormone? a. The MAPK cascade leading to cell activation is defective in the target cells. b. The DNA sequence it binds to underwent a mutation. c. There is no intracellular receptor for thyroid hormone in the cell. d. The second messenger does not recognize the signal from the receptor.
c
Why are carnivores, such as lions, dependent on photosynthesis to survive? a. because the prey of lions are generally herbivores which depend on heterotrophs b. because the prey of lions are generally smaller carnivorous animals which depend on non-photosynthetic organisms c. because the prey of lions are generally herbivores which depend on autotrophs d. because the prey of lions are generally omnivores that depend only on autotrophs.
c
In photosynthesis, plants use carbon from ______________ to make sugar and other organic molecules.
carbon dioxide
Inorganic cations or large organic molecules such as vitamins assist enzyme activation. The organic molecules that activate enzymes are known as ______________.
coenzymes
The division of cytoplasm at the end of mitosis is known as __________________.
cytokinesis
In Substrate-level phosphorylation, phosphate (PO4 3-) group from an organic molecule is transferred to ADP to make ATP. The location where substrate-level phosphorylation occurs is ____________.
cytosol
In Substrate-level phosphorylation, phosphate (PO4 3-) group from an organic molecule is transferred to ADP to make ATP. The location where substrate-level phosphorylation occurs is
cytosol
A doctor is researching new ways to treat biofilms on artificial joints. Which approach would best help prevent bacterial colonization of the medical implants? a. Increase antibiotic dosing b. Create implants with rougher surfaces c. Vaccinate patients against all pathogenic bacteria d. Inhibit quorum sensing
d
A new species of obligate anaerobe, a bacterium, has been found that lives in hot, acidic conditions. While other pathways may also be present, which metabolic pathway is the most likely to be present in this species? a.aerobic respiration b.the citric acid cycle c.oxidative phosphorylation d.glycolysis
d
A scientist notices that a cancer cell line fails to die when he adds an inducer of apoptosis to his culture of cells. Which hypothesis could explain why the cells fail to die? a. The cells have a mutation that prevents the initiation of apoptosis signaling. b. The cells have lost expression of the receptor for the apoptosis-inducing ligand. c. The cells overexpress a growth factor pathway that inhibits apoptosis. d. All of the above.
d
As temperatures increase, gases such as CO2CO2 diffuse faster. As a result, plant leaves will lose CO2CO2 at a faster rate than normal. If the amount of light impacting on the leaf and the amount of water available is adequate, predict how this loss of gas will affect photosynthesis in the leaf. a. Loss of gases, mainly CO2CO2, will not affect photosynthesis in the leaf, as adequate amounts of water and light are still present which will let the Calvin cycle run smoothly. b. Loss of gases, mainly CO2CO2, will affect photosynthesis in the leaf, as the Calvin cycle will become faster to compensate for the loss. c. Loss of gases, mainly CO2CO2, will not affect photosynthesis in the leaf, as stored reservoirs of CO2CO2 in the leaf can be utilized in such times. d. Loss of gases, mainly CO2CO2, will affect photosynthesis in the leaf, as the Calvin cycle will slow down and possibly stop because of inadequate carbon to fix in the system.
d
If a drug blocks the phosphorylation of I-κB and release from NF-κB, what is the outcome for the cell? a. aAuto-phosphorylation of RTK is blocked. b. The RAS protein is not activated. c. The MAPK kinase cascade is blocked. d. Transcription is not activated.
d
Molecules do not flow between the endothelial cells in the brain capillaries. The membranes of the cells must be joined by what? a. gap junctions b. ligand-gated channels c. synapses d. tight junctions
d
The same second messengers are used in many different cells, but the response to second messengers is different in each cell. How is this possible? a. Different cells produce the same receptor, which bind to the same ligands, but have a different response in each cell type. b. Cells produce variants of a particular receptor for a particular ligand through alternative splicing, resulting in different response in each cell c. Cells contain different genes, which produce different receptors that bind to same ligand, activating different responses in each cell. d. Cells produce different receptors that bind to the same ligand or the same receptor that binds to the same ligand with different signaling components, activating different responses in each cell.
d
What is the external source of the electrons that ultimately pass through photosynthetic electron transport chains? a. carbon dioxide b. NADPH c. oxygen d. water
d
Which of the following statements is true? a. In photosynthesis, oxygen, carbon dioxide, ATP and NADPH are reactants. GA3P and water are products. b. In photosynthesis, chlorophyll, water and carbon dioxide are reactants. GA3P and oxygen are products. Chlorophyll captures light energy, but has no role to play in the photosynthesis reactions. c. In photosynthesis, water, carbon dioxide, ATP and NADPH are reactants. RuBP and oxygen are products. d. In photosynthesis, water and carbon dioxide are reactants. GA3P and oxygen are products.
d
Which of the following produces the most ATP when glucose (C6H12 O6) is completely oxidized to carbon dioxide (CO2) and water? A. glycolysis B. fermentation C. oxidation of pyruvate to acetyl CoA D. citric acid cycle E. oxidative phosphorylation (chemiosmosis)
e
Chemical reactions in which the products have more energy than the reactants are known as ___________ reactions.
endothermic
Ordered display of all metaphase chromosomes is generated to diagnose certain genetic disorders. Such display is called a ________________
karyotype
In Oxidative phosphorylation is addition of phosphate (PO4 3-) to ADP yields ATP. Name the location where this process process takes place
matrix
In Oxidative phosphorylation is addition of phosphate (PO4 3-) to ADP yields ATP. Name the location where this process process takes place ______________.
matrix
When does the random assortment of chromosomes occur in meiosis?
metaphase I
Asexual reproduction results in identical offspring unless which of the following occurs?
mutation
The viscous fluid inside the inner chloroplast membrane where Calvin cycle occurs is known as ___________.
stroma
In photophosphorylation (PO43-) + ADP → ATP is catalyzed by the enzyme ATP synthase, which is located in the ________ membrane.
thylakoid
In photophosphorylation (PO43-) + ADP → ATP is catalyzed by the enzyme ATP synthase, which is located in the ____________ membrane.
thylakoid
When a cell receives continuous signal to divide, tumor or cancer can result. true false
true
The world's most abundant protein is an enzyme found in chloroplast. It can build sugar or break it down by photorespiration. This enzyme is called _____________.
{RuBisCo}