AP BIO UNIT 4

What is the blue/purple part called? what is the center called?

1) Chromosomes or chromatids 2) Centromeres

Give three reasons why cells need to divide

1) repair 2) decrease surface area 3) growth and reproduction

If a cell with 16 chromosomes undergoes mitosis, how many chromosomes will be in each daughter cell?

16

Glycogen synthetase kinase 3 beta is a protein kinase that has been implicated in many types of cancer. Depending on the cell type, the gene for glycogen synthetase kinase 3 beta (GSK3B) can act either as an oncogene or as a tumor suppressor. Which of the following best predicts how GSK3B mutations can lead to the development of cancer? A) cells with inactive GSK3B fail to trigger apoptosis. B) cells with inactive GSK3B fail to proceed past the G2 /M checkpoint. C) cells with overactive GSK3B are more likely to repair the DNA damage. D) cells with overactive GSK3B have longer cell cycles.

A) cells with inactive GSK3B fail to trigger apoptosis.

Sister chromatids are pulled apart to opposite ends of the cell. This description is identifying what stage of the cell cycle?

Anaphase.

What is the process that allows for the separation of two new daughter cells?

Cytokinesis.

Cancer cells behave differently than normal body cells. For example, they ignore signals that tell them to stop dividing. Which of the following conditions will most likely cause a normal body cell to become a cancer cell? A) the environment already contains cancer cells. B) the environment has an abundance of nutrients. C) the environment lacks signals that would otherwise tell the cell to stop dividing. D) the environment contains mutagens that induce mutations that affect cell-cycle regulatory proteins.

D) the environment contains mutagens that induce mutations that affect cell-cycle regulatory proteins.

The release of the hormone epinephrine into the bloodstream to stimulate the fight or flight response is an example of what type of signaling?

Endocrine signaling (long distance)

What would happen if a ligand permanently binds to and activates its receptor on a target cell?

If it permanently binds and activates to a receptor it would continuously set off signals.

How does apoptosis play a role in cancer?

If the mutated/cancerous cell does not respond to apoptosis (cell death) then the cell will continue to grow and divide.

What is the advantage of a multi-step signal transduction pathway?

It amplifies the signal faster and creates better regulation.

What happens if the cell cycle is not regulated and the check points are not functioning properly?

It could result in cancer.

What is the role of cAMP?

It is a second messenger that amplifies the signal.

What is paracrine signaling. Give an example.

Paracrine signaling allows cells to communicate with each other by releasing signaling molecules that bind to and activate surrounding cells. An example would be the synapse in nerve cells.

Nuclear envelope disappears and the chromosomes condense. The spindle forms. This description is identifying what stage of the cell cycle?

Prophase.

Identify this stage of the cell cycle

Telophase

The nuclear envelope reforms and the chromosomes begin to uncoil. This description is identifying what stage of the cell cycle?

Telophase.

In which stage of the cell cycle does DNA replicate—be specific

The S phase of Interphase.

What is the result of a loss of p53 function?

The cell would either die or be mutated.

Predict the effects on the cell cycle of a drug designed to interfere with the production of cyclin molecules. Provide reasoning for why this drug treats cancer.

The cell would not progress in the cycle. So this would stop cancerous cell from further growth.

Predict the effects on the cell cycle of a class of drugs called microtubule inhibitors. Provide reasoning for why these drugs treat cancer.

The microtubule inhibitors would stop the cells division because they would inhibit spindle fibers which act as the "guide wires". These drugs could stop the cancer cells from producing more cancerous cells.

Would a hydrophilic molecule bind a cell surface receptor or diffuse through the plasma membrane?

They would bind to a cell surface receptor because the hydrophilic molecule would not be able to pass through the cell membrane.

Small non-polar molecules will bind to intracellular or extracellular receptors?

intracellular because the molecule can diffuse through the cell membrane.