B1a cell structure- side two

Question 1

rearrange these from smallest to largest.

nucleus, DNA, gene, chromosome, cell

Answer 1

cell
nucleus
chromosome 
dna
gene

Question 2

what happens in the cell cycle?

Answer 2

genetic material is doubled and then divided into two identical cells

Question 3

What is stage one of the cell cycle?

Answer 3

Growth

increase the number of sub- cellular structures eg. ribosomes and mitochondria

Question 4

What is stage two of the cell cycle

Answer 4

DNA synthesis

DNA replicates to form two copies of each chromosome

Question 5

What is stage three of the cell cycle

Answer 5

Mitosis
One set of chromosomes is pulled into each end of the cell and the nucleus divides
then the cytoplasm and cell membranes divide to form two identical cells

Question 6

Human embryonic stem cell

Answer 6

Can be cloned and made to differentiate into most cell types

treatment with stem cells- diabetes/ paralysis etc.

Question 7

adult bone marrow stem cell

Answer 7

can form into many types of human cells eg. blood cells

treatment with stem cells- diabetes/ paralysis

Question 8

meristems (plants- in the growing tips of shoots and roots)

Answer 8

can differentiate into any plant cell type throughout the life of the plant
used to produce clones quickly and economically eg. rare species can be cloned to protect from extinction

Question 9

stem cell advantages (2)

Answer 9

in therapeutic cloning, an embryo is made with the same genes as the patient so the body does not reject the tissue
with adult bone marrow tissue can be matched to avoid rejection

Question 10

stem cell disadvantage (4)

Answer 10

risk of infection with therapeutic cloning eg. transfer of viruses
with adult bone marrow only a few types of cells can be formed
some people object on religious grounds
some people object on ethical grounds