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- What is chromatin? a. the histone-containing protein core of the nucleosome b. the 30-nm fiber c. the complex of DNA and proteins found in the nucleus d. the histone and non-histone proteins in eukaryotic nuclei
Problem 1
Problem 2
After S phase, what makes up a single chromosome?
a. Two daughter chromosomes
b. A double-stranded DNA molecule
c. Two single-stranded DNA molecules
d. Two sister chromatids
Problem 3
Progression through the cell cycle is regulated by oscillations in the concentration of which type of molecule?
a. p53, Rb, and other tumor suppressors
b. Receptor tyrosine kinases
c. Cyclins
d. Cyclin-dependent kinases
Problem 4
What major events occur during anaphase of mitosis?
- What major events occur during anaphase of mitosis?
Problem 4
Problem 5
Identify at least two events in the cell cycle that must be completed successfully for daughter cells to share an identical complement of chromosomes.
Problem 6
What evidence suggests that during anaphase, kinetochore microtubules shorten at the kinetochore?
- What evidence suggests that during anaphase, kinetochore microtubules shorten at the kinetochore?
Problem 6
- The following statements are about the control of chromatin condensation. Select True or False for each. T/F Reducing histone acetylase activity is likely to decrease gene transcription. T/F Mutations that reduce the number of positively charged amino acids on histones should promote open chromatin. T/F Chromatin remodeling complexes add chemical groups to histones. T/F Adding an inhibitor of DNA methylation is likely to reduce gene transcription.
Problem 7
Problem 8
Compare and contrast the effects of removing growth factors from asynchronous cultures of human cells that are normal and those that are cancerous.
Problem 9
A particular cell type spends 4 hours in G1 phase, 2 hours in S-phase, 2 hours in G2 phase, and 30 minutes in M-phase. If a pulse-chase experiment were performed with radioactive thymidine on an asynchronous culture of such cells, what percentage of mitotic cells would be radiolabeled 9 hours after the pulse?
a. 0 percent
b. 50 percent
c. 75 percent
d. 100 percent
Problem 10
When a fruit fly embryo first begins to develop, a large cell is generated that contains over 8000 genetically identical nuclei. What is most likely responsible for this result?