mitosis/the cell cycle

Question 1

What is mitosis

Answer 1

It’s the division of cells that result in each each of the daughter cells having an exact copy of the DNA of the parent cell. Mitosis always occurs when the cell is not dividing this is called interphase

Question 2

What happens in prophase

Answer 2

The chromosomes first become visible initially as long thin threads which later shorten and thicken. The centrioles move to opposite ends and spindle fibres develop.the nucleolus disappears and the nuclear envelope breaks down. The chromosomes are drawn towards the equator of the cell by the spindle fibres

Question 3

What happens in metaphase

Answer 3

The chromosomes are seen to be made up of two chromatids and each chromatid is identical copy of DNA from the parent cell. The chromatids are joined by the centromere and the poles are attached and the chromosomes are pulled along the spindle apparatus and arrange themselves across the equator of the cells.

Question 4

What is anaphase

Answer 4

The centromeres divide into 2 and the spindle fibres pull the individual chromatids making up the chromosome apart. The chromatids move rapidly to their respective opposite poles of the cell and are now chromosomes. The energy for this is from mitochondria.

Question 5

What is the telophase

Answer 5

The chromosome have reached there respective poles and are longer and thinner.finally disappearing altogether leaving only widely spread chromatin. The spindle fibres disintegrate and the nuclear envelope and nucleolus re form finally the cytoplasm divides in a process called cytokinesis

Question 6

Replication in viruses

Answer 6

They cant undergo cell division they replicate by attaching to their host cell with the attachment proteins

Question 7

What three stages does the cell cycle have

Answer 7

Interphase
Nuclear division
Division of the cytoplasm

Question 8

How long is the cell cycle

Answer 8

It 24 hours of which 90% is interphase

Question 9

What does cancer cause

Answer 9

Uncontrolled growth of cells and this is called a tumour

Question 10

What are some treatments of cancer

Answer 10

Using chemo therapy to either Preventing DNA from replicating
Inhibiting the metaphase dates of mitosis by interfering with spindle formation