Exam 10: How Cells Divide

You are leading a team of researchers at a pharmaceutical company.Your goal is to design drugs that help fight cancer.Specifically, you want to focus on drugs that bind to and inactivate certain proteins, thereby halting cell cycle progression.One of your team members suggests targeting the retinoblastoma (Rb) protein and inhibiting this protein.Will this approach be successful? Why or why not?

In G₂, there are typically high levels of the mitotic cyclin.Why is cdc2 not active during G₂ if the mitotic cyclin is present?

Following S phase, a human cell would have how many pairs of sister chromatids and individual DNA molecules?

You are examining the effect of maturation-promoting factor (MPF) in sea urchin cells, which have a diploid number of 36.If you fuse a dividing sea urchin cell with a G₁ arrested oocyte, what would be the outcome?

You are assembling a model of a chromosome, but begin having some trouble when you get to the step of forming chromatin loops.If you are unable to resolve this problem, what step of chromosome structure would you be unable to achieve?

A somatic cell from a corn plant normally contains 20 chromosomes.How many sister chromatids would that cell contain during G2 of the cell cycle?

What time point represents G₂?

In prophase, ribosomal RNA synthesis stops when the chromosomes condense, and as a result:

The division of a bacterial cell occurs as the:

Embryonic cell cycles allow the rapid division of cells in the early embryo.These mitotic cell cycles are much shorter in length than the mitotic cell cycles of cells in a mature organism.In the embryonic cell cycles, mitosis takes approximately the same amount of time as it does in the cell cycles of mature cells.What do you think is a result of the embryonic cycle?

The accommodation of the very long DNA strands that are part of a chromosome into the limited space of the nucleus is achieved by coiling the DNA around beads of histones into repeating subunits.These DNA-wrapped histones are called:

This stage of the cell cycle is characterized by growth and it contains a checkpoint to verify that all of the DNA has been replicated prior to mitosis.

Before cell division of somatic cells, each chromosome must be replicated.After replication, the resulting two parts of each chromosome are held together by cohesin at the centromere.These two parts are referred to as:

If there are 32 sister chromatids in a normal somatic cell, what is the haploid number for that cell?

The two copies of each type of chromosome found in normal somatic (body) cells in an organism, throughout the cell cycle, are called:

If you were to think of the cell as a car, and mitosis as a process that drives that car to go, what would be a good analogy for a cell that has a mutation in both copies of a tumor-suppressor gene?

Interphase is made up of what stages of the cell cycle?

A duplicate copy of all of the hereditary information contained in the nucleus of eukaryotic cells is made during what stage of the cell cycle?

During what stages of the cell cycle are sister chromatids bound together by cohesin?

You are conducting a genetic screen using Caenorhabditis elegans embryos to isolate mutations affecting anaphase (A).Therefore, you need to look for embryos in which