Mitosis: The Cell Cycle

Question 1

Describe the distribution of chromosomes during cell division.

Answer 1

DNA is replicated and the chromosomes condense
Each duplicated chromosome has two sister chromatids, which separate during cell division
The centromere is the waist of the duplicated chromosome, where two chromatids are most closely attached

Question 2

The human genome formula

Answer 2

2n = 46
23 pairs of chromosomes
2 copies of each chromosome per cell

Question 3

What are the phases for mitosis?

Answer 3

Prophase, Prometaphase, Metaphase, Anaphase, Telophase

Question 4

What is pro metaphase and what proteins are involved?

Answer 4

the nuclear envelope dissolves by the mending of Laminators and YFP

Question 5

What does Mitosis preserve?

Answer 5

the chromosome number, 46 bodies in metaphase

Question 6

What is Metaphase?

Answer 6

the sister chromatids align on plate

Question 7

What is Anaphase?

Answer 7

sister chromatids separate and move along the kinetochore microtubules toward opposite ends of the cell
microtubules shorten by depolymerizing at their kinetochore ends
nonkinetochore microtubules from opposite poles overlap and push against each other, elongating the cell

Question 8

How is cytokinesis different in animal cells and plant cells

Answer 8

animal: occurs by cleavage, to form a cleavage furrow
plant: cell plate forms during cytokinesis

Question 9

What is the cell cycle control system

Answer 9

the sequential events of the cell cycle are directed by a distinct cell cycle control system, which is similar to a clock
regulated by internal and external controls
has specific checkpoints where the cell cycle stops until a go-ahead signal is received

Question 10

What contributes to the cell cycle control system

Answer 10

Regulatory Proteins: cyclin and cyclin-dependent kinases (Cdks)
activity fluctuates during the cell cycle
MPF is a cyclin-CDK complex that triggers a cell’s passage past the G2 checkpoint into M phase

Question 11

What is a kinase

Answer 11

an enzyme that phosphorylates proteins to activate their functions.

Question 12

Describe Cyclin in cell cycle clock

Answer 12

CDK is used during G1 and G2
cyclin is synthesized during S phase
At G2 checkpoint, cyclin and CDK bond and degrade during M phase
Cycle breaks away and is degraded
CDK enters back into G1