AP Bio Final 2019

Based on Figure 1, what percent of the time required to complete a full cycle do the cells typically spend in interphase?

• 5

• 35

• 50

• 95

Which of the following is true of mitosis?

• It is also known as cytokinesis.

• It maintains the same chromosome number in the daughter cells as in the parent cell.

• It is the last phase of interphase.

• It regulates the transfer of genetic information from one daughter cell to another.

Which of the following best describes the role of mitosis in the cell cycle?

• Distributing replicated chromosomes to daughter nuclei

• Dividing the cytoplasm to form four gametes

• Producing organelles and replicating chromosomes

• Exchanging genetic material between homologous chromosomes

If chemical signals in the cytoplasm control the progression of a cell to the M phase of the cell cycle, then fusion of a cell in G1 with a cell in early M phase would most likely result in the

• replication of chromosomes only in the G1 cell

• exiting of both cells from the cell cycle and into the G0 phase

• condensation of chromatin in preparation of nuclear division in both cells

• transfer of organelles from the G1 cell to the cell in the M phase

Most cells that have become transformed into cancer cells have which of the following characteristics when compared to normal, healthy cells?

• Shorter cell cycle

• More carefully regulated rates of cell division

• Lower rates of mitosis

• Higher rates of protein translation

Which of the following conditions will most likely cause a normal body cell to become a cancer cell?

• The environment already contains cancer cells.

• The environment has an abundance of nutrients.

• The environment lacks signals that would otherwise tell the cell to stop dividing.

• The environment contains mutagens that induce mutations that affect cell-cycle regulator proteins.

Which of the following best predicts how GSK3β mutations can lead to the development of cancer?

• Cells with inactive GSK3β fail to trigger apoptosis.

• Cells with inactive GSK3β fail to proceed past the G2/M checkpoint.

• Cells with overactive GSK3β are more likely to repair DNA damage.

• Cells with overactive GSK3β have longer cell cycles.

During mitosis, which of the following normally occurs?

• Homologous chromosomes pair.

• Replicated chromosomes line up on the equatorial plate.

• Tetrads form.

• Unreplicated chromosomes become oriented in the center of the cell.

Cancer can result from a variety of different mutational events. Which of the following is LEAST likely to result in the initiation of a cancerous tumor?

• A receptor mutation results in activation of a cell-division pathway in the absence of the appropriate ligand.

• A mutation results in the loss of the ability to produce a tumor-suppressor protein.

• A defect in a cell-cycle checkpoint prevents a cell from entering the S phase.

• At the anaphase checkpoint, separation of chromatids occurs without all centromeres being attached to kinetochore microtubules from both poles.

A researcher examining a root tip observes a plant cell with condensed sister chromatids, kinetochores with attached microtubules, and individual chromosomes that are aligned at the equatorial plate of the cell. Which of the following best describes what the next process will be in the cell?

• Homologous chromosomes (each with two sister chromatids) will move toward opposite poles of the cell.

• Paired chromatids will separate, and the new daughter chromosomes will move toward opposite poles of the cell.

• The nuclear envelope will break down, and the spindle will begin to form.

• The chromatin will decondense, and the daughter cell will enter interphase.