Mastering Biology #6 (Lec. 24-28)

Question 1

Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active?
Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active?
protein kinase
cyclin
PDGF
MPF
Cdk

Answer 1

CDK

Question 2

The MPF protein complex turns itself off by
The MPF protein complex turns itself off by
activating the anaphase-promoting complex.
exiting the cell.
binding to chromatin.
activating a process that destroys cyclin components.
activating an enzyme that stimulates cyclin.

Answer 2

activating a process that destroys cyclin components.

Question 3

The decline of MPF activity at the end of mitosis is due to
The decline of MPF activity at the end of mitosis is due to
decreased synthesis of Cdk.
the accumulation of cyclin.
the degradation of cyclin.
the destruction of the protein kinase Cdk.

Answer 3

the degradation of cyclin

Question 4

Two sister chromatids are joined at the centromere prior to meiosis. Which statement is correct?
Two sister chromatids are joined at the centromere prior to meiosis. Which statement is correct?
Unless there was a mutation, the two sister chromatids are identical.
The two sister chromatids stay together all through meiosis II.
The cell that contains these sister chromatids must be diploid after meiosis I.
These chromatids make up a diploid chromosome.

Answer 4

Unless there was a mutation, the two sister chromatids are identical.The chromosome is duplicated during DNA replication, and the formed sister chromatids are kept together by cohesion molecules.

Question 5

hat is the function of meiosis?
What is the function of meiosis?
to make cells with a haploid (half that of the parents) number of chromosomes
to make exact copies of the parent cell
to make one cell with twice the number of chromosomes as the parent pairs
to make four cells with the same chromosome number as the parent
to make diploid spores

Answer 5

to make cells with a haploid (half that of the parents) number of chromosomes Correct
The two cell divisions of meiosis, I and II, produce four haploid daughter cells, which are not genetically identical to the diploid parent cell.

Question 6

If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be
If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be
0.25x.
2x.
x.
0.5x.

Answer 6

D) 2x