Cell Development ReviewCell Development Review

Eukaryotic sexual life cycles show Eukaryotic sexual life cycles show tremendous variation. Of the following tremendous variation. Of the following elements, which do elements, which do allall sexual life cycles sexual life cycles have in common?have in common? I. Alternation of generationsI. Alternation of generations II. MeiosisII. Meiosis III. FertilizationIII. Fertilization IV. GametesIV. Gametes V. SporesV. Spores(A) I, IV, and V (A) I, IV, and V (C) II, III, and IV (C) II, III, and IV (B) I, II, and IV (B) I, II, and IV (D) II, IV, and V(D) II, IV, and V

After telophase I of meiosis, the After telophase I of meiosis, the chromosomal makeup of each daughter chromosomal makeup of each daughter cell iscell is(A) diploid, and the chromosomes are each (A) diploid, and the chromosomes are each composed of a single chromatid. composed of a single chromatid. (B) diploid, and the chromosomes are each (B) diploid, and the chromosomes are each composed of two chromatids. composed of two chromatids. (C) haploid, and the chromosomes are (C) haploid, and the chromosomes are each composed of a single chromatid. each composed of a single chromatid. (D) haploid, and the chromosomes are (D) haploid, and the chromosomes are each composed of two chromatids. each composed of two chromatids.

How do cells at the completion of meiosis How do cells at the completion of meiosis compare with cells that have replicated their compare with cells that have replicated their DNA and are just about to begin meiosis?DNA and are just about to begin meiosis?(A) They have twice the amount of cytoplasm (A) They have twice the amount of cytoplasm and half the amount of DNA. and half the amount of DNA. (B) They have half the number of (B) They have half the number of chromosomes and half the amount of DNA. chromosomes and half the amount of DNA. (C) They have the same number of (C) They have the same number of chromosomes and half the amount of DNA. chromosomes and half the amount of DNA. (D) They have half the number of (D) They have half the number of chromosomes and one-fourth the amount of chromosomes and one-fourth the amount of DNA. DNA.

What could happen to the target cells in an What could happen to the target cells in an animal that lack receptors for local animal that lack receptors for local regulators?regulators?A. They could compensate by receiving A. They could compensate by receiving nutrients via an nutrients via an aa factor. factor. B. They could develop normally in response to B. They could develop normally in response to neurotransmitters instead. neurotransmitters instead. C. They could divide but never reach full size. C. They could divide but never reach full size. D. They would not be able to multiply in D. They would not be able to multiply in response to growth factors from nearby cells. response to growth factors from nearby cells. E. Hormones would not be able to interact E. Hormones would not be able to interact with target cells. with target cells.

When a cell releases a signal molecule When a cell releases a signal molecule into the environment and a number of into the environment and a number of cells in the immediate vicinity cells in the immediate vicinity respond, this type of signaling isrespond, this type of signaling is

A. typical of hormones. A. typical of hormones.

B. autocrine signaling. B. autocrine signaling.

C. paracrine signaling. C. paracrine signaling.

D. endocrine signaling. D. endocrine signaling.

E. synaptic signaling. E. synaptic signaling.

Of the following, a receptor protein in a Of the following, a receptor protein in a membrane that recognizes a chemical signal membrane that recognizes a chemical signal is most similar tois most similar toA. the active site of an allosteric enzyme in A. the active site of an allosteric enzyme in the cytoplasm that binds to a specific the cytoplasm that binds to a specific substrate. substrate. B. RNA specifying the amino acids in a B. RNA specifying the amino acids in a polypeptide. polypeptide. C. a particular metabolic pathway operating C. a particular metabolic pathway operating within a specific organelle. within a specific organelle. D. an enzyme with an optimum pH and D. an enzyme with an optimum pH and temperature for activity. temperature for activity. E. genes making up a chromosome. E. genes making up a chromosome.

Chiasmata are what we see under a microscope that let us know which of the following is occurring?

A. Asexual reproduction

B. Meiosis II

C. Anaphase II

D. Crossing over

E. Separation of homologs

Testosterone functions inside a cell byTestosterone functions inside a cell byA. acting as a signal receptor that activates A. acting as a signal receptor that activates ion-channel proteins. ion-channel proteins. B. binding with a receptor protein that enters B. binding with a receptor protein that enters the nucleus and activates specific genes. the nucleus and activates specific genes. C. acting as a steroid signal receptor that C. acting as a steroid signal receptor that activates ion-channel proteins. activates ion-channel proteins. D. becoming a second messenger that inhibits D. becoming a second messenger that inhibits adenylyl cyclase. adenylyl cyclase. E. coordinating a phosphorylation cascade E. coordinating a phosphorylation cascade that increases glycogen metabolism. that increases glycogen metabolism.

Which of the following describes the events of Which of the following describes the events of apoptosis?apoptosis?A. The cell dies, it is lysed, its organelles are A. The cell dies, it is lysed, its organelles are phagocytized, its contents are recycled. phagocytized, its contents are recycled. B. Its DNA and organelles become fragmented, it B. Its DNA and organelles become fragmented, it dies, and it is phagocytized. dies, and it is phagocytized. C. The cell dies and the presence of its C. The cell dies and the presence of its fragmented contents stimulates nearby cells to fragmented contents stimulates nearby cells to divide. divide. D. Its DNA and organelles are fragmented, the D. Its DNA and organelles are fragmented, the cell shrinks and forms blebs, and the cell self-cell shrinks and forms blebs, and the cell self-digests. digests. E. Its nucleus and organelles are lysed, the cell E. Its nucleus and organelles are lysed, the cell enlarges and bursts. enlarges and bursts.

Which term describes centromeres Which term describes centromeres uncoupling, sister chromatids uncoupling, sister chromatids separating, and the two new separating, and the two new chromosomes moving to opposite poles chromosomes moving to opposite poles of the cell?of the cell?A. telophase A. telophase B. anaphase B. anaphase C. prometaphase C. prometaphase D. metaphase D. metaphase E. prophaseE. prophase

Why do chromosomes coil during Why do chromosomes coil during mitosis?mitosis?A. to increase their potential energy A. to increase their potential energy B. to allow the chromosomes to move B. to allow the chromosomes to move without becoming entangled and without becoming entangled and breaking breaking C. to allow the chromosomes to fit C. to allow the chromosomes to fit within the nuclear envelope within the nuclear envelope D. to allow the sister chromatids to D. to allow the sister chromatids to remain attachedremain attached

This is the shortest part of the cell This is the shortest part of the cell cycle:cycle:

A. GA. G00 B. G B. G11 C. S D. G C. S D. G22 E. M E. M

Density-dependent inhibition is explained by Density-dependent inhibition is explained by which of the following?which of the following?A. As cells become more numerous, they begin to A. As cells become more numerous, they begin to squeeze against each other, restricting their size squeeze against each other, restricting their size and ability to produce control factors. and ability to produce control factors. B. As cells become more numerous, the cell B. As cells become more numerous, the cell surface proteins of one cell contact the adjoining surface proteins of one cell contact the adjoining cells and they stop dividing. cells and they stop dividing. C. As cells become more numerous, the protein C. As cells become more numerous, the protein kinases they produce begin to compete with each kinases they produce begin to compete with each other, such that the proteins produced by one cell other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. essentially cancel those produced by its neighbor. D. As cells become more numerous, more and D. As cells become more numerous, more and more of them enter the S phase of the cell cycle. more of them enter the S phase of the cell cycle.

Eukaryotic sexual life cycles show Eukaryotic sexual life cycles show tremendous variation. Of the following tremendous variation. Of the following elements, which do elements, which do allall sexual life cycles sexual life cycles have in common?have in common?I. Alternation of generationsI. Alternation of generationsII. MeiosisII. MeiosisIII. FertilizationIII. FertilizationIV. GametesIV. GametesV. SporesV. Spores

A. I, IV, and V A. I, IV, and V C. II, III, and IV C. II, III, and IV B. I, II, and IV B. I, II, and IV D. II, IV, and VD. II, IV, and V

Which number represents DNA Which number represents DNA synthesis?synthesis?

A. I B. II C. III D. IV E. VA. I B. II C. III D. IV E. V

G1 is represented by which G1 is represented by which number(s)?number(s)?

A. I and V A. I and V

B. II and IV B. II and IV

C. III C. III

D. IV D. IV

E. VE. V

Vinblastine is a standard Vinblastine is a standard chemotherapeutic drug used to treat chemotherapeutic drug used to treat cancer. Because it interferes with the cancer. Because it interferes with the assembly of microtubules, its effectiveness assembly of microtubules, its effectiveness must be related tomust be related toA. disruption of mitotic spindle A. disruption of mitotic spindle formation. formation. B. inhibition of regulatory protein B. inhibition of regulatory protein phosphorylation. phosphorylation. C. suppression of cyclin production. C. suppression of cyclin production. D. myosin denaturation and inhibition of D. myosin denaturation and inhibition of cleavage furrow formation.cleavage furrow formation.

How do cells at the completion of meiosis How do cells at the completion of meiosis compare with cells that have replicated their compare with cells that have replicated their DNA and are just about to begin meiosis?DNA and are just about to begin meiosis?A. They have twice the amount of cytoplasm A. They have twice the amount of cytoplasm and half the amount of DNA. and half the amount of DNA. B. They have half the number of B. They have half the number of chromosomes and half the amount of DNA. chromosomes and half the amount of DNA. C. They have the same number of C. They have the same number of chromosomes and half the amount of DNA. chromosomes and half the amount of DNA. D. They have half the number of D. They have half the number of chromosomes and one-fourth the amount of chromosomes and one-fourth the amount of DNA.DNA.

Meiosis II is similar to mitosis in thatMeiosis II is similar to mitosis in thatA. sister chromatids separate during A. sister chromatids separate during anaphase. anaphase. B. DNA replicates before the division. B. DNA replicates before the division. C. the daughter cells are diploid. C. the daughter cells are diploid. D. homologous chromosomes synapse. D. homologous chromosomes synapse. E. the chromosome number is reduced.E. the chromosome number is reduced.

In general, a signal transmitted via In general, a signal transmitted via phosphorylation of a series of proteinsphosphorylation of a series of proteinsA. brings a conformational change to A. brings a conformational change to each protein. each protein. B. requires binding of a hormone to a B. requires binding of a hormone to a cytosol receptor. cytosol receptor. C. cannot occur in yeasts because they C. cannot occur in yeasts because they lack protein phosphatases. lack protein phosphatases. D. requires phosphorylase activity. D. requires phosphorylase activity. E. allows target cells to change their E. allows target cells to change their shape and therefore their activity.shape and therefore their activity.

The termination phase of cell signaling The termination phase of cell signaling requires which of the following?requires which of the following?

A. removal of the receptor A. removal of the receptor

B. activation of a different set of relay B. activation of a different set of relay molecules molecules

C. converting ATP to cAMP C. converting ATP to cAMP

D. reversing the binding of signal D. reversing the binding of signal molecule to the receptor molecule to the receptor

E. apoptosisE. apoptosis

How do the daughter cells at the end of mitosis How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell and cytokinesis compare with their parent cell when it was in Gwhen it was in G11 of the cell cycle? of the cell cycle?

A. The daughter cells have half the amount of A. The daughter cells have half the amount of cytoplasm and half the amount of DNA. cytoplasm and half the amount of DNA. B. The daughter cells have half the number of B. The daughter cells have half the number of chromosomes and half the amount of DNA. chromosomes and half the amount of DNA. C. The daughter cells have the same number of C. The daughter cells have the same number of chromosomes and half the amount of DNA. chromosomes and half the amount of DNA. D. The daughter cells have the same number of D. The daughter cells have the same number of chromosomes and the same amount of DNA. chromosomes and the same amount of DNA. E. The daughter cells have the same number of E. The daughter cells have the same number of chromosomes and twice the amount of DNA.chromosomes and twice the amount of DNA.

Taxol is an anticancer drug extracted from Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, taxol the Pacific yew tree. In animal cells, taxol disrupts microtubule formation by binding to disrupts microtubule formation by binding to microtubules and accelerating their assembly microtubules and accelerating their assembly from the protein precursor, tubulin. from the protein precursor, tubulin. Surprisingly, this stops mitosis. Specifically, Surprisingly, this stops mitosis. Specifically, taxol must affecttaxol must affectA. the fibers of the mitotic spindle. A. the fibers of the mitotic spindle. B. anaphase. B. anaphase. C. formation of the centrioles. C. formation of the centrioles. D. chromatid assembly. D. chromatid assembly. E. the S phase of the cell cycle.E. the S phase of the cell cycle.

If mammalian cells receive a go-ahead If mammalian cells receive a go-ahead signal at the Gsignal at the G11 checkpoint, they will checkpoint, they will

A. move directly into telophase. A. move directly into telophase.

B. complete the cycle and divide. B. complete the cycle and divide.

C. exit the cycle and switch to a C. exit the cycle and switch to a nondividing state. nondividing state.

D. show a drop in MPF concentration. D. show a drop in MPF concentration.

E. complete cytokinesis and form new E. complete cytokinesis and form new cell walls.cell walls.

Which of the following describe(s) cyclin-Which of the following describe(s) cyclin-dependent kinase (Cdk)?dependent kinase (Cdk)?I. Cdk is inactive, or "turned off," in the I. Cdk is inactive, or "turned off," in the presence of cyclin.presence of cyclin.II. Cdk is present throughout the cell II. Cdk is present throughout the cell cycle.cycle.III. Cdk is an enzyme that attaches III. Cdk is an enzyme that attaches phosphate groups to other proteins.phosphate groups to other proteins.A. I only A. I only D. II and III only D. II and III only B. II only B. II only E. I, II, and IIIE. I, II, and IIIC. I and II onlyC. I and II only

The karyotype of one species of primate The karyotype of one species of primate has 48 chromosomes. In a particular has 48 chromosomes. In a particular female, cell division goes awry and she female, cell division goes awry and she produces one of her eggs with an extra produces one of her eggs with an extra chromosome (25). The most probable chromosome (25). The most probable source of this error would be a mistake in source of this error would be a mistake in which of the following?which of the following?A. Mitosis in her ovary A. Mitosis in her ovary B. Metaphase I of one meiotic event B. Metaphase I of one meiotic event C. Telophase II of one meiotic event C. Telophase II of one meiotic event D. Telophase I of one meiotic event D. Telophase I of one meiotic event E. Either anaphase I or IIE. Either anaphase I or II

Which of the following happens at the Which of the following happens at the conclusion of meiosis I?conclusion of meiosis I?A. Homologous chromosomes are A. Homologous chromosomes are separated. separated. B. The chromosome number per cell is B. The chromosome number per cell is conserved. conserved. C. Sister chromatids are separated. C. Sister chromatids are separated. D. Four daughter cells are formed. D. Four daughter cells are formed. E. The sperm cells elongate to form a E. The sperm cells elongate to form a head and a tail end.head and a tail end.

Whether during mitosis or meiosis, sister Whether during mitosis or meiosis, sister chromatids are held together by proteins chromatids are held together by proteins referred to as cohesions. Such molecules must referred to as cohesions. Such molecules must have which of the following properties?have which of the following properties?A. They must persist throughout the cell cycle. A. They must persist throughout the cell cycle. B. They must be removed before meiosis can B. They must be removed before meiosis can begin. begin. C. They must be removed before anaphase can C. They must be removed before anaphase can occur. occur. D. They must reattach to chromosomes during D. They must reattach to chromosomes during G1. G1. E. They must be intact for nuclear envelope E. They must be intact for nuclear envelope reformation.reformation.

Minutes Spent in Cell Cycle Phases

The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma. Of the following, the best conclusion concerning the difference between the S phases for beta and gamma is thatA. gamma contains more DNA than beta. B. beta and gamma contain the same amount of DNA. C. beta contains more RNA than gamma. D. gamma contains 48 times more DNA and RNA than beta. E. beta is a plant cell and gamma is an animal cell.

You have isolated DNA from three different cell types of an organism, determined the relative DNA content for each type, and plotted the results.Which sample might represent an animal cell in G2 phase of the cell cycle?

A. I D. Either I or II B. II E. Either II or IIIC. III

You have isolated

DNA from three

different cell types of

an organism,

determined the relative DNA

content for each type, and plotted the results.

Which sample might represent a sperm cell?

A. I D. Either I or II

B. II E. Either II or III

C. III

You have isolated DNA from three different cell types of an organism, determined the relative DNA content for each type, and plotted the results.Which sample of DNA might be from a nerve cell arrested in G0 of the cell cycle?A. I D. Either I or II B. II E. Either II or IIIC. III

1. Formation of four new nuclei, each with half the chromosomes present in the parental nucleus2. Alignment of tetrads at the metaphase plate3. Separation of sister chromatids4. Separation of the homologues; no uncoupling of the centromere5. Synapsis; chromosomes moving to the middle of the cell in pairs From the descriptions above, which of the following is the order that most logically illustrates a sequence of meiosis?A. 1, 2, 3, 4, 5 D. 4, 5, 2, 1, 3 B. 5, 4, 2, 1, 3 E. 5, 2, 4, 3, 1C. 5, 3, 2, 4, 1

An inhibitor of phosphodiesterase activity would have which of the following effects?A. block the response of epinephrine B. decrease the amount of cAMP in the cytoplasm C. block the activation of G proteins in response to epinephrine binding to its receptor D. prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm E. block the activation of protein kinase A

Lipid-soluble signal molecules, such as testosterone, cross the membranes of all cells but affect only target cells because

A. only target cells retain the appropriate DNA segments. B. intracellular receptors are present only in target cells. C. most cells lack the Y chromosome required. D. only target cells possess the cytosolic enzymes that transduce the testosterone. E. only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor.

Consider this pathway: epinephrine G protein-coupled receptor G protein adenylyl cyclase cAMP. Identify the second messenger.

A. cAMP

B. G protein

C. GTP

D. adenylyl cyclase

E. G protein-coupled receptor

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

Which of the following are primarily responsible for cytokinesis in plant cells?

A. kinetochores

B. Golgi-derived vesicles

C. actin and myosin

D. centrioles and basal bodies

E. cyclin-dependent kinases

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei re-forming on either side of the cell plate. This cell is most likelyA. an animal cell in the process of cytokinesis. B. a plant cell in the process of cytokinesis. C. an animal cell in the S phase of the cell cycle. D. a bacterial cell dividing.

A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following?

A. It must be human.

B. It must be a primate.

C. It must be an animal.

D. It must be sexually reproducing.

E. Its gametes must have 23 chromosomes.

Chromatids are separated from each other.A. The statement is true for mitosis only. B. The statement is true for meiosis I only. C. The statement is true for meiosis II only. D. The statement is true for mitosis and meiosis I. E. The statement is true for mitosis and meiosis II.

A tetrad includes which of the following sets of DNA strands?

A. Two single-stranded chromosomes that have synapsed

B. Two sets of sister chromatids that have synapsed

C. Four sets of sister chromatids

D. Four sets of unique chromosomes

E. Eight sets of sister chromatids

Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels ofA. phosphorylated proteins. B. GTP. C. cAMP. D. adenylyl cyclase. E. activated G proteins.

Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction becauseA. they are species specific. B. they always lead to the same cellular response. C. they amplify the original signal many fold. D. they counter the harmful effects of phosphatases. E. the number of molecules used is small and fixed.

One inhibitor of cGMP is Viagra. It provides a signal that leads to dilation of blood vessels and increase of blood in the penis, facilitating erection. cGMP is inhibited, therefore the signal is prolonged. The original signal that is now inhibited would have

A. hydrolyzed cGMP to GMP. B. hydrolyzed GTP to GDP. C. phosphorylated GDP. D. dephosphorylated cGMP. E. removed GMP from the cell.

If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested?A. anaphase B. prophase C. telophase D. metaphase E. interphase

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

You have in your possession a microscope slide with meiotic cells on it and a light microscope. What would you look for if you wanted to identify metaphase I cells on the slide?A. A visible nuclear envelope B. Separated sister chromatids at each pole of the cell C. Tetrads lined up at the center of the cell D. A synaptonemal complex E. A cleavage furrow

A mutation results in a cell that no longer produces a normal protein kinase for the M phase checkpoint. Which of the following would likely be the immediate result of this mutation?A. The cell would prematurely enter anaphase. B. The cell would never leave metaphase. C. The cell would never enter metaphase. D. The cell would never enter prophase. E. The cell would undergo normal mitosis, but fail to enter the next G1 phase.