B5 - Animal Development

Question 1

….. stem cells are able to divide and develop into any type of cell. The …. genes determine the cell it will develop into. These are …. stem cells, and through …. they divide. They are …. until the 8 cell stage and can develop into cells including n….e cells and b….d cells.

Answer 1

Stem, active, embryonic, mitosis, unspecialised, nerve, blood.

Question 2

At the 8 cell stage the cells d…….e and are able to specialise to develop tissues, ….. of cells, and organs, groups of……

Answer 2

differentiate, groups, tissues.

Question 3

What is the issue with adult stem cells compared to embryonic stem cells?

Answer 3

They can only develop into certain cells. For example, stem cells in bone marrow.

Question 4

People with …… cell anaemia can be treated with …. marrow transplants. This contains …. cells which develop into ….. cells as they specialise to cure this.

Answer 4

sickle, bone, stem, white blood,

Question 5

Embryonic stem cells are …… and can treat diseases such as h….. d……! Conditions are controlled to control the genes which …. on in differentiation when the cells divide to produce the cells needed.

Answer 5

undifferentiated, heart disease, switch,

Question 6

How can clones be used to cure illness?

Answer 6

1. Take a egg cell.
2. Remove the nucleus.
3. Place the nucleus of a body cell in the egg cell and place the cell in warm nutrients to stimulate the nucleus’s genes to reactivate. Then, the embryo divides.
4. Collect the stem cells and control conditions so that the specialised cells needed can be collected.

Question 7

What’s the difference between embryonic and adult stem cells?

Answer 7

Embryonic stem cells can differentiate into any type of specialised cell. Adult stem cells can become specialised but they’re not as versatile.

Question 8

Once an egg is fertilised it divides by …. and forms an …. made of embryonic ….. ! These cells can divide to produce any type of …. cell. After the … cell stage the cells form …. and organs.

Answer 8

mitosis, embryo, stem cells, specialised, eight, tissues.

Question 9

How are stem cells used in medicine?

Answer 9

To repair damaged tissue.

Question 10

Most cells are specialised to do a particular job such as carry o….n around the body.

Answer 10

Oxygen