Cell division Lesson 1 (Year 10)

What is cell division?

Cell division is when a parent cell divides into two genetically identical daughter cells, mostly through mitosis and division of the cytoplasm.

What is Mitosis used for?

Growth and repair

What is Meiosis used for?

Reproduction and producing sperm and egg cells, but also pollen.

What is Step 1 of mitosis? And how many chromosomes are in it?

Step 1 of mitosis is when the cell becomes bigger and its organelles duplicate.

46 chromosomes.

Why does the cell need to become bigger?

The cell needs to become bigger so that when it splits, the daughter cells don't become smaller and smaller until they eventually disappear.

What is Step 2 of mitosis? And how many chromosomes are in it?

Step 2 of mitosis is when the chromosomes duplicate, and become short and thick. The nucleus membrane also disappears.

92 chromosomes.

What is Step 3 of mitosis? And how many chromosomes are in it?

Step 3 of mitosis is when the chromosomes line up in the equator of the cell.

92 chromosomes.

What is Step 4 of mitosis? And how many chromosomes are in it?

The spindle fibres pull on the chromosomes to each of the poles.

92 chromosomes.

What is Step 5 of mitosis? And how many chromosomes are in it?

The nucleus reforms and the cytoplasm divides into two daughter cells.

42 chromosomes.

What is the name of the process that takes place in Step 5?

Cytokinesis

What are cells with two sets of chromosomes called?

Diploids

What are cells with one set of chromosomes called?

Haploid cells

What type of cells only have one set of chromosomes?

Gametes (sex cells)

What type of cell division would they use?

Meiosis