Cell Cycle and Mitosis EXAM

Question 1

What are the two reasons why cells have to divide?

Answer 1

• To replace damaged, worn out cells
• DNA overload

Question 2

In a living cell, what part of the cell represents surface area and which part of the cell represents volume?

Answer 2

The cell membrane represents surface area, and the cytoplasm represents volume.

Question 3

What are some adaptations that cells have developed that allow for a greater surface area volume ratio?

Answer 3

• can divide!
• Can slow down their metabolism
• Can change shape

Question 4

Cell division occurs in two main stages. What are they?

Answer 4

Mitosis and cytokinesis.

Question 5

What is the cell cycle?

Answer 5

process of cell division

Question 6

What are the 4 stages of the cell cycle?
Explain each stage.

Answer 6

• G1 phase: Dna / chromosomes are duplicated (growing phase 1)
• S-phase: synthesis phase
• G2 phase: division of the parent cell’s cytoplasm
• Mitosis (M phase): Cell prepares to divide and divides

Question 7

What is the G0 stage? Give 3 examples of cells that stay here.

Answer 7

The phase for cells that never divide once they are made.
- Red blood cells
- sperm/egg cells
- Cardiac cells

Question 8

Cells spend most of their lifetime in what stage? What 3 phases of the cell cycle does this include?

Answer 8

nterphase - including the G1, S, and G2 phases.

Question 9

What are the four stages of mitosis, in order?

Answer 9

• PMAT
  prophase, metaphase, anaphase, telophase

Question 10

Briefly describe what happens in each of the four stages of mitosis.

Answer 10

• Prophase: nuclear envelope breaks down, chromatin condenses into chromosomes.
• Metaphase: Nucleus dissolves, chromosomes meet in the middle
• Anaphase: sister chromatids are pulled to opposite ends of the cell
• Telophase: 2 membranes are formed around 2 identical sister nuclei

Question 11

explain how six feet of DNA is packed into the nucleus of every cell of our body!

Answer 11

The DNA wraps around proteins called histones and further around nucleosomes. This forms loosely coiled chromatin. Then in mitosis it becomes tightly wound and becomes a chromosome

Question 12

How many chromosomes are found in human body cells? How many chromosomes are found in human sex cells (egg and sperm)?

Answer 12

46 in body cells and 23 in sex cells.

Question 13

What is the name of the proteins that regulate the cell cycle?

Answer 13

Cyclin

Question 14

What causes cancer?

Answer 14

• Carcinogens: smoking, tabaco, radiation
• Viral infection
• Genetics (p53)
• Poor lifestyle

Question 15

What is apoptosis?

Answer 15

• Programed cell death (cell self-destruction)
• Shapes tissues and organs
• When this doesn’t occur, diseases happen
  EX. AIDS and parkinson’s disease
• They’re supposed to, and cancer cells don’t

Question 16

what is angiogenisis?

Answer 16

when cancer calles shunt blood supply to themselves and stave the healthy ones

Question 17

How often do people get cancer
(men and women speratly)

Answer 17

1-2 men and 2-3 women get cancer