B2 END OF HALF TERM TEST YR10

Question 1

Cell division

Why do cells need to divide?

Answer 1

To allow is to grow
To repair body tissues( e.g. muscle, bone)
To replace worn out/ damaged cells
To produce sex cells

Question 2

What is Mitosis?

Answer 2

Normal body cells divide by mitosis e.g. skin cells

Question 3

What is Meiosis?

Answer 3

The type of cell division that produces sex cells (sperm and egg cells)

Question 4

There are 3 stages of the cell cycle

What happens in Interphase?

Answer 4

Start of the cell cycle 
Cell prepares itself to divide 
The cell grows in size 
The DNA is replicated(doubled) 
The organelles (mitochondria and ribosomes) are replicated

Question 5

What happens in Mitosis?

Answer 5

Second stage of the cell cycle
Chromosomes line up along the centre of the cell
They attach to the spindle fibres
Spindle fibres contract
Chromosomes get pulled to opposite ends of the cell
The nucleus divides

Question 6

What happens in Cytokinesis?

Answer 6

The cytoplasm and cell membrane divide

Two new genetically identical(daughter) cells are formed

Question 7

What can a stem cell do?

Answer 7

Can replicate many times

Has the potential to become specialised (e.g. different types of cell)

Question 8

What is a stem cell?

Answer 8

It is a cell that has not yet become a specialised cell(undifferentiated)

Question 9

There are 2 types of stem cells

What is an Embryonic stem cell?

Answer 9

They are found in embryos and can differentiate into almost every cell type under the right conditions in a lab

Question 10

What is an Adult stem cell?

Answer 10

They are found in adult tissues(such as bone marrow, brain, muscle, liver stem cells).
They can differentiate only into cells from the type of tissue where they are found.
E.g. Liver stem cells can only become liver cells

Question 11

Where are plant stem cells found?

Answer 11

In the meristems of a plant

Question 12

Where are meristems found?

Answer 12

Tips of shoots
Tips of roots
Where growth is happening

Question 13

What is Therapeutic cloning?

Answer 13

It is the process of creating stem cells with the same genes as the patient. This would prevent rejection

Question 14

What are the steps in therapeutic cloning?

Answer 14

Nucleus taken out of a human egg cell
Nucleus from a patient’s cell put into the egg cell
Egg cell simulated to divide develops into an embryo
Stem cells taken from the embryo after 4-5 days
Stem cells grown in a container of warm nutrients
Stem cells treated to develop into required cell types for a patient.