Chapter 19 Practice Set

Mitotic cyclin is at its lowest level. G1 S G2 M none of the phases

M

Sister chromatids separate from each other. G1 S G2 M none of the phases

M

The nuclear envelope breaks into fragments. G1 S G2 M none of the phases

M

The primary cell wall of a plant cell forms. G1 S G2 M none of the phases

M

Which of the following outcomes would you expect to see if Ras were to acquire a mutation in which its GTPase activity were abolished? GTP will not bind to Ras. MAP kinases will be continuously activated, promoting continual and repeating mitotic divisions. MAP kinases will not be activated. Cyclin will be degraded.

MAP kinases will be continuously activated, promoting continual and repeating mitotic divisions.

Mutations that inactivate the main protein phosphatase used to catalyze protein dephosphorylations cause a long delay in the reconstruction of the nuclear envelope that normally takes place at the end of mitosis. Proteins dephosphorylated by mitotic Cdk-cyclin at the beginning of anaphase must be phosphorylated again before cells can finish mitosis Proteins phosphorylated by mitotic Cdk-cyclin at the beginning of prophase must be dephosphorylated again before cells can finish mitosis Proteins phosphorylated by mitotic Cdk-cyclin at the beginning of anaphase must be dephosphorylated again before cells can finish mitosis Proteins dephosphorylated by mitotic Cdk-cyclin at the beginning of prophase must be phosphorylated again before cells can finish mitosis

Proteins phosphorylated by mitotic Cdk-cyclin at the beginning of prophase must be dephosphorylated again before cells can finish mitosis

The amount of nuclear DNA in the cell doubles. G1 S G2 M none of the phases

S

Which of the following would be expected if the Rb protein were mutated such that it could not be phosphorylated by cyclin-dependent kinases? The cell will not be able to enter S phase. The cell will enter S phase but not be able to exit S phase. Rb will activate the apoptosome. Rb will degrade securin and promote anaphase too early.

The cell will not be able to enter S phase.

Cyclins modulate the progression of cells through the cell cycle by activating protein kinases that are critical regulators of cell division. directly activating G proteins. degrading histones. increasing the production of DNA polymerases. inducing synthesis of constitutively active forms of growth cell receptors.

activating protein kinases that are critical regulators of cell division.

A particular strain of yeast produces strains with a mutant cdc2 gene, resulting in little to no production of the Cdc2 protein kinase. As a result, one would expect that these cells would not have the nuclear envelope disperse. lack chromosome condensation. not enter M phase. all of the above none of the above

all of the above

In the cell cycle, a mitotic Cdk is present during G1. G2. S. M. all of the above

all of the above

Which of the following would NOT be a potential signal the cell would need in order to progress through the G1 checkpoint? The necessary extracellular cues should be present (growth factors, etc...). sufficient nucleotides and nutrients for DNA synthesis an active p53 protein lack of DNA damage

an active p53 protein

Phosphorylation of ________ is required for chromosome condensation. condensin DNA gyrase topoisomerase II cyclin cyclin and condensin

condensin

Which of the following eukaryotic DNA polymerases replicates mitochondrial DNA? gamma epsilon beta alpha delta

gamma

Which of the following is NOT a mechanism used to temporally regulate the activity of maturation-promoting factor (MPF)? specific phosphorylation specific dephosphorylation the presence of mitotic cyclin glycosylation

glycosylation

The proteins most actively synthesized during the S phase of the cell cycle are rRNA proteins. cyclins. histones. single-strand binding proteins. DNA polymerases.

histones.

The longest phase of the cell cycle is prophase. telophase. anaphase. metaphase. interphase.

interphase.

The phase of the cell cycle associated with the replication of DNA is prophase. telophase. metaphase. interphase. anaphase.

interphase.

DNA replication proceeds by making two continuous strands. is conservative. is partially regulated by promoter/terminator sites. is not edited once polymerization has occurred. requires a type of RNA polymerase.

requires a type of RNA polymerase.

DNA replication is dispersive. irregular. semiconservative. conservative. none of the above

semiconservative.

In order to be active, a Cdc-cyclin needs to be singly phosphorylated. doubly methylated. doubly phosphorylated. cleaved by proteases. acetylated.

singly phosphorylated.

Which of the following proteins is observed exclusively in association with eukaryotic DNA replication? single-strand binding proteins DNA polymerase I DNA ligase telomerase DNA gyrase

telomerase

A mitotic Cdk-cyclin complex __________. inhibits chromosome condensation triggers entry into mitosis activates mitotic proteins by dephosphorylation stabilizes the nuclear envelope

triggers entry into mitosis

In the cell cycle, controlled degradation of regulatory proteins occurs via the kinase inhibition pathway. P450 - protease pathway. cyclin proteolysis pathway. ubiquitin-proteosome pathway. none of the above

ubiquitin-proteosome pathway.

Which of the following statements regarding DNA replication is true? Cyclin-dependent kinases (Cdk) are not involved in the DNA replication process. Bacterial replication is faster than eukaryotic replication. The rate of DNA replication is constant at all stages of development in eukaryotes. DNA replication during embryonic development occurs at a slower rate than in the early stages of neonatal life. Early-replicating genes are those that are not actively transcribed.

Bacterial replication is faster than eukaryotic replication.

G2 and M Chromosomes are in an condensed form during G2, but in an extended form during most of M phase. M has the 2C amount of DNA; G2 has the 4C amount. During M phase chromosomes are invisible, and in G2 they are visualized. Chromosomes are in an extended form during G2, but in a condensed form during most of M phase.

Chromosomes are in an extended form during G2, but in a condensed form during most of M phase.

G1 and S G1 has the 2n amount of DNA; S has the 4n amount. DNA is being synthesized during S; little or no synthesis occurs during G1. During S phase chromosomes are invisible; in G1 they are visualized. Chromosomes are in an extended form during S; in a condensed form during G1.

DNA is being synthesized during S; little or no synthesis occurs during G1.

During the G2 checkpoint in eukaryotic cells, the cell is assessed with regard to DNA replication. nutrients. chromosome attachment to the spindle. presence of growth factors. DNA damage.

DNA replication.

When an abnormal, indestructible form of mitotic cyclin is introduced into cells, they enter into mitosis but cannot emerge from it and reenter G1 phase. Destruction of mitotic cyclin - and hence the inactivation of mitotic Cdk - are required before cells can complete mitosis and begin a new cell cycle. Destruction of mitotic cyclin - and hence the inactivation of mitotic Cdk - are not required before cells can complete mitosis and begin a new cell cycle. Destruction of mitotic cyclin - and hence the activation of mitotic Cdk - are not required before cells can complete mitosis and begin a new cell cycle. Destruction of mitotic cyclin - and hence the activation of mitotic Cdk - are required before cells can complete mitosis and begin a new cell cycle.

Destruction of mitotic cyclin - and hence the inactivation of mitotic Cdk - are required before cells can complete mitosis and begin a new cell cycle.

When mitotic Cdk-cyclin is injected into cells that have just emerged from S phase, chromosome condensation and nuclear envelope breakdown occur immediately, rather than after the normal G2 delay of several hours. Select the four correct statements. Mitotic Cdk-cyclin catalyzes the phosphorylation of condensins and lamins. Mitotic Cdk-cyclin inhibits the phosphorylation of condensins and lamins. It is possible to trigger chromosome condensation and nuclear envelope breakdown prematurely by experimentally introducing mitotic Cdk-cyclin into cells that have just emerged from G2 phase. Phosphorylation of condensins and lamins contributes to chromosome condensation and nuclear envelope breakdown. Mitotic Cdk-cyclin is normally activated at the end of S. Phosphorylation of condensins and lamins prevents chromosome condensation and nuclear envelope breakdown. It is possible to trigger chromosome condensation and nuclear envelope breakdown prematurely by experimentally introducing mitotic Cdk-cyclin into cells that have just emerged from S phase. Mitotic Cdk-cyclin is normally activated at the end of G2.

1. Mitotic Cdk-cyclin catalyzes the phosphorylation of condensins and lamins. 2. Phosphorylation of condensins and lamins contributes to chromosome condensation and nuclear envelope breakdown. 3. It is possible to trigger chromosome condensation and nuclear envelope breakdown prematurely by experimentally introducing mitotic Cdk-cyclin into cells that have just emerged from S phase. 4. Mitotic Cdk-cyclin is normally activated at the end of G2.

Which enzyme is involved in proofreading during DNA replication? Which enzyme is involved in proofreading during DNA replication? 5' to 3' exonuclease 5' to 3' endonuclease 3' to 5' endonuclease DNA polymerase 3' to 5' exonuclease

3' to 5' exonuclease

G1 and M DNA is being synthesized during M; little or no synthesis occurs during G1. G1 has the 2C amount of DNA; M has the 4C amount. During M phase chromosomes are invisible; in G1 they are visualized. Chromosomes are in an extended form during G1, but in a condensed form during most of M phase.

Chromosomes are in an extended form during G1, but in a condensed form during most of M phase.

Cells that will never divide again are likely to be arrested in this phase. G1 S G2 M none of the phases

G1

This phase is part of interphase. Select all that apply. G1 S G2 M none of the phases

G1 S G2

A Cdk protein is present in the cell. Select all that apply. G1 S G2 M none of the phases

G1 S G2 M

A cell cycle checkpoint has been identified in this phase. Select all that apply. G1 S G2 M none of the phases

G1 S G2 M

Chromosomes are present as diffuse, extended chromatin. Select all that apply. G1 S G2 M none of the phases

G1 S G2

G1 and G2 DNA is being synthesized during G1; little or no synthesis occurs during G2. Chromosomes are in an extended form during G2; in a condensed form during G1. G1 has the haploid set of DNA; G2 has the diploid set. G1 has the 2C amount of DNA; G2 has the 4C amount.

G1 has the 2C amount of DNA; G2 has the 4C amount.