B2: Cell division (including stem cells)

Why are chromosomes found in pairs in the body?

You get one from each parent

What are two identical cells called?

Daughter cells

What is the type of cell division that occurs during growth and repair called?

Mitosis

when your DNA is being replicated what is it being check for?

Mistakes

What happens when mistakes are found in the DNA that is being replicated?

If the mistakes will damage the cell and repairs cannot be made, the cell is destroyed before being replicated.

Step 1: What happens during interphase? (4 steps)

• cell grows

• All contents of the cell is copied

• DNA is doubled to make 2 copies of the chromosome

• Genetic material is checked for mistakes

Step 2: What happens during mitosis? (2 steps)

• The nucleus splits into two

• Chromosomes move apart

Step 3: What happens during cytokinesis? (2 steps)

• cytoplasm divides into two

• New cell membranes are formed to give two identical daughter cells

Define stem cells

Unspecialised cells that are able to turn into other cells

Define embryonic stem cells

Unspecialised cells that have the ability to turn into any type of cell

After how long is the ball of cells from fertilisation called an embryo and what are they referred to as?

About 1 week and these are unspecialised cells called embryonic stem cells

Why are stem cells needed in adult animals?

To replace worn out and damaged cells

Why can stem cells be used for therapeutic use?

They can be used to treat disease, illness or conditions as they become new cells to replace the damaged ones

In and embryo what do stem cells become?

All the different types of cells needed to form the foetus

Why are stem cells needed in meristem?

For grown and different parts of the plant

Where in the body are adult stem cells found?

Bone marrow

Name 2 medical conditions that can could be treated with embryonic stem cells in the future

• heart disease

• Diabetes