3.8 The cell cycle

Question 1

What are the three stages of the cell cycle

Answer 1

Interphase-occupies most of the cell cycle
Nuclear division-Nucleus divides either into two (mitosis) or four (meiosis)
Cytokinesis-Division of the cell, cytoplasm divides to produce two new cells for four

Question 2

Define cancer

Answer 2

A group of diseases caused by a growth disorder of cells.
It is the result of damage to the genes that regulate mitosis and the cell cycle.This leads to uncontrollable cell growth

Question 3

What is a malignant tumour

Answer 3

A rapid growing tumour which is more likely to be life threatening as they can spread across the body
Cancerous

Question 4

What is a benign tumour

Answer 4

A slower growing tumour that stayes in one place they are also more compact
Non cancerious

Question 5

How is cancer treated

Answer 5

By blocking a part of the cell cycle (chemotherapy)

Question 6

How does chemotherapy disrupt the cell cycle

Answer 6

Prevents DNA from replicating
Inhibiting the metaphase stage of mitosis by interferring with spindle formation

Question 7

What is the problem with drugs like chemo

Answer 7

It also disrupts the cell cycle of normal cells
Chemo targets the cells that rapidly divide like cancer cells but this also attacks hair cells as they also divide rapidly

Question 8

Suggest hiw cancer treatments control the rate of cell division

Answer 8

*Some disrupt the spindle fibre activity/formation
-This is so chromosomes cant attach to spindle by thier centromere
-so chromatids cant be separated to opposite poles (no anaphase)
-So prevents/ slows mitosis
*Some prevent DNA repliation during interphase
-So cant make 2 copies of each chromosome
-So prevents/slows mitosis

Question 9

Describe hjow tumors and cancers form

Answer 9

*Mutations in DNA can lead to uncomntrollanble cell divison
* Tumor formed if this results in mass of abnromal cells