Cell division - mitosis

Question 1

How do body cells divide?

Answer 1

By mitosis, which is a stage in the cell cycle.

Question 2

Why do multicellular organisms use mitosis?

Answer 2

To grow and develop or replace cells that have been damaged.

Question 3

What is mitosis?

Answer 3

When a cell reproduces it self by splitting to form two identical offspring.

Question 4

What are the two stages in the cell cycle?

Answer 4

Cell growth and DNA replication

Mitosis

Question 5

What happens during the growth and replication stage?

Answer 5

1. The cell has to grow and increase the amount of subcellular structures (e.g. mitochondria, ribosomes)
2. DNA is then duplicated - one copy of each chromosome for each cell. DNA forms X-shaped chromosomes, each arm is an exact copy of the other.

Question 6

What happens during mitosis?

Answer 6

1. Chromosomes line at centre of cell + fibres pull them apart. Two arms of each chromosome go to opposite ends of the cell.
2. Membranes form around each of the sets of chromosomes - these become nuclei of two new cells (nucleus has divided)
3. Cytoplasm and cell membrane divide.

Question 7

When does the cell cycle start and end?

Answer 7

Starts when a cell has been produced by cell division and ends with the cell dividing to produce two identical cells.

Question 8

What are the results of the cell cycle?

Answer 8

Results in two new cells identical to the original cell, with the same number of chromosomes.