B2

Question 1

How is cell division in mitosis important in fully grown/mature animals

Answer 1

Because it helps repair tissue/replace cells

Question 2

What do chromosomes do?

Answer 2

Carry the genes for making all the new cells, tissues and organs in an organism

Question 3

Gene

Answer 3

A small packet of DNA that controls a characteristic in an organism

Question 4

How many chromosomes are in the nucleus of your body cells

Answer 4

46, arranged in 23 pairs

Question 5

Areas with continued growth/replacement of cells
(due to mitosis)

Answer 5

Hair follicles
Skin
Blood
Lining of digestive system

Question 6

Is mitosis quicker in a child or adult?

Answer 6

In a child

Question 7

How long is the cell cycle?

Answer 7

Depends on the cells involved and the stage of life of the organism. The cell cycle is a short as a baby develops new cells before it’s born, increases during childhood but slows down when an adult goes through puberty.

Question 8

Growth

Answer 8

A permanent increase in size as a result of cell division/enlargement

Question 9

Adult stem cells

Answer 9

Replaces dead or damaged differentiated cells that can’t divide e.g. red blood cells and skin cells

Question 10

Cloning

Answer 10

Producing identical offspring

Question 11

Animal cloning

Answer 11

It’s difficult to clone animals as they differentiate early in their embryo development.

Question 12

Embryonic stem cells

Answer 12

Form as the egg and sperm cell fuse to form a zygote and
this cell divides to become a hollow ball of cells - the inner cells here are the embryonic stem cells. These cells can differentiate into any type of cell needed in the body.

Question 13

Adult stem cell

Answer 13

Undifferentiated cell of an organism that can give rise to many more cells of the same type

Question 14

Problems with embryonic stem cells

Answer 14

Ethical concerns
Could cause cancer
Slow/difficult progress

Question 15

Problems with adult stem cells

Answer 15

Could be infected with a virus
Could trigger an immune response
Patient may need some immunosuppressant drugs

Question 16

Therapeutic cloning

Answer 16

Using cells from an adult to produce a cloned early embryo of themselves. This provides a source of embryonic stem cells.

Question 17

Advantages of therapeutic cloning

Answer 17

The embryonic stem cells produced are used for medical treatments
New organs made from the original donor in a medical treatment won’t be rejected by body as they’ve been made from the body’s own cells and have the same genes

Question 18

Where are plant stem cells

Answer 18

Meristems

Question 19

Gene

Answer 19

A section of DNA that controls the development of specific characteristics in an organism.

Question 20

Zygote

Answer 20

The single new cell formed by the fusion of gametes in sexual reproduction

Question 21

How can stem cells treat diabetes?

Answer 21

Stem cells can turn into the special insulin-producing cells in the pancreas that are so important for controlling blood sugar.

Question 22

Disadvantages of therapeutic cloning

Answer 22

Poor success rate
Shortage of donors/eggs

Question 23

One economic use of plant stem cells

Answer 23

To produce large numbers of identical plants

Question 24

1 nanogram

Answer 24

-9
10 g