Exam 4 part 2

Question 1

What are the two main phases of the cell cycle? What are their subphases

Answer 1

Interphase includes G1, S phase and G2

M phase includes Prophase, prometaphase, metaphase, anaphase and telophase

Question 2

What is the purpose of the Gap phases of interphase

Answer 2

They are checkpoints that make sure the cell is ready to move on the next phase

Question 3

How do chromosomes differ between the G1 and G2 phases

Answer 3

G1 = unreplicated 
G2 = replicated

Question 4

When do chromosomes condense during M phase

Answer 4

Prophase of Mitosis; right at the beginning

Question 5

What are the two types of microtubules and how do they differ functionally

Answer 5

Kinetochore microtubules – pulling chromosomes toward opposite poles
Polar microtubules – pushing on poles to pull ends apart

Question 6

1. During what M-phase subphase do chromosomes line up along a central plane in the cell?

Answer 6

metaphase

Question 7

During what subphase do sister chromatids divide

Answer 7

anaphase

Question 8

How can the cell cycle differ across cell types

Answer 8

The speed
For example, brain cells last a very long time
Cells in digestive tract do not

Question 9

How do chromosomes migrate toward the cell poles during anaphase

Answer 9

Disassembled at kinetochore and chromosomes are being pushed during disassembly towards the poles so the cell is ready to divide

Question 10

During cytokinesis, describe how plants and animals divide their cytoplasm

Answer 10

Plants – vesicles line up

Animals – actin and myosin filaments pinch until there is two daughter cells

Question 11

What are the components of MPF and how do they differ

Answer 11

Mitosis Promoting Factor…2 components are cylin and kinase.
Cylin is regulating when the cell division occurs (telling kinase what to do) and kinase actually carrying out phosphorylation (which means the addition of a phosphate group)

Question 12

When is concentration of the Cyclin component of MPF the highest and what triggers MPF’s activation for mitosis?

Answer 12

Two phosphates will join, then one is removed, and that’s what activates the MPF and then the cell begins Mitosis

Question 13

When does MPF degrade

Answer 13

Happens in Anaphase
The enzymes are targeting the cyclin
Kinase stays same concentration throughout cell cycle

Question 14

When do the checkpoints for the cell cycle occur and what is their purpose

Answer 14

In interphase:
G1
G2
In M phase: 
Two in M phase 

If they don’t pass these checkpoints, they are marked for Apoptosis using p53

Question 15

What is the function of p53

Answer 15

Signal saying cell needs to be degraded because it’s having problems.
If it’s not degraded, it will cause cancer

Question 16

What is cancer caused by

Answer 16

Cells that grow in an uncontrolled fashion
Invade nearby tissues
Spread to other sites on the body

Question 17

What is the difference between a benign tumor and a malignant tumor

Answer 17

Benign tumors are noninvasive and noncancerous.

Malignant tumors are invasive, cancerous, can spread throughout body via the blood or lymph, initiate secondary tumors

Question 18

When malignant tumors detach from the original tumor and invade other tissues, it is called what

Answer 18

metastasis