U1 KA1&2

Question 1

What is a stem cell?

Answer 1

Site of production of specialised cells,
Involved in growth and repair found in certain locations of the body.

Question 2

Example of Tissue

Answer 2

Blood, muscle or nerve.

Question 3

Example of Organ

Answer 3

Kidney, Skin or Heart.

Question 4

Example of Systems

Answer 4

Digestive or nervous.

Question 5

Example of organisms

Answer 5

Human.

Question 6

Why is cell division necessary in cells?

Answer 6

Allows organisms to grow,
To replace damaged cells and repair tissue.

Question 7

How is the chromosome complement maintained during cell division?

Answer 7

DNA replicates so there are 2 copies of each chromosome,
As the nucleus divides the chromatically are separated and each of the daughter cells will receive 1 copy.

Question 8

What is a somatic cell?

Answer 8

Differentiated body cells that aren’t gamates ,
They are found throughout the body.

Eg. Teeth

Question 9

What process divides somatic cells?

Answer 9

Mitosis.

Question 10

What cells are formed after somatic cells experience mitosis?

Answer 10

Identical diploid daughter cells.

Question 11

What is a germ line cell?

Answer 11

It is a cell that divides to produce more germ line cells and haploid gamates.
They are found in ovaries and testes.

Question 12

What process do germline cells divide by?

Answer 12

a. Division by mitosis (to make germline)
b. Division by meiosis (to make gamates)

Question 13

The nucleus of a germline cell can divide by mitosis to maintain the…

Answer 13

Chromosome complement.

Question 14

Diploid cells have how many chromosomes?

Answer 14

46

Question 15

Describe the process of meiosis

Answer 15

The nucleus of a germline cell can divide by meiosis it undergoes 2 divisions.
1st is seoeraginf homologous chromosomes.
2nd is separating chromatids.

Question 16

What is cellular differentiation?

Answer 16

The process by which a cell expresses genes to produce proteins characteristics for that type of cell.

Question 17

Why does cellular differentiation need to take place?

Answer 17

Cells become differentiated so that different cells become specialised to carry our specific functions, rather than all cells carrying all functions.

Question 18

What type of cells do specialised cells form?

Answer 18

Stem.

Question 19

Embryonic stem cells.

Answer 19

Cells in very early embryo can differentiate into all the cell types that make up the individual, so are pluripotent.

Question 20

Why can embryo cells do what they do?

Answer 20

All genes in the embryo can be switched on so these cells can differentiate into any type of cell.

Question 21

What is a tissue stem cell?

Answer 21

Involved in the growth + repair and renewal of the cells found in that tissue.

Eg.skin (multipotent)

Question 22

What does multipotent mean ?

Answer 22

They can differentiate into all of the cells found in a particular tissue.

Question 23

What does pluripotent mean?

Answer 23

cells that are able to self-renew by dividing

Question 24

Examples of cells a blood stem cell can produce?

Answer 24

Red blood cells,
Platelets,
Phagocytes,
Lymphocytes.

Question 25

Difference between embryonic stem and tissue.

Answer 25

Embryonic stem cells have the potential to differ into any type of body cell,
Tissue stem cells can differ into cells from tissue they are found.

Question 26

What genes are expressed from a red blood cell?

Answer 26

Haemoglobin production.

Question 27

What genes does a platelet express?

Answer 27

Genes for healing associated proteins.

Question 28

Phagocytes express what genes?

Answer 28

Digestive enzymes.

Question 29

Lymphocytes express which kind of genes?

Answer 29

Cell killing proteins & cytosines.

Question 30

Therapeutic uses for stem cells?

Answer 30

-repair of cornea
-regeneration of damaged skin.

Question 31

Suggest a benefit of using of tissue stem cells medicinally?

Answer 31

No risk of rejection.

Question 32

For what purposes are stem cells used as model cells in research?

Answer 32

-how disease develops.
- used for drug tests.

Question 33

What type of cell processes does stem cell research provide information on?

Answer 33

-increase understanding of how disease occurs.
-differentiation.
-gene regulation.

Question 34

Why may there be ethical concerns relating to using embryonic stem cells?

Answer 34

It involves the destruction of human embryos.

Question 35

Why do cancer cells divide excessively?

Answer 35

They do not respond to regulatory signals.

Question 36

What is a tumour?

Answer 36

A mass of abnormal cells.

Question 37

What does a nucleotide contain?

Answer 37

Deoxyribose sugar, phosphate, bases.

Question 38

What’s a sugar phosphate backbone?

Answer 38

Nucleotides join together when a strong chemical bond forms between the phosphate of a nucleiotide and a deoxyribose sugar of another nucleotide.

Question 39

What’s complementary base pairing?

Answer 39

2 strands of dna nucleotides are joined together by weak hydrogen bonds between base pairs.

Question 40

What are anti parallel strands?

Answer 40

Each strand has a 5’ end and 3’ end,
When both strands join they run in opposite directions.

Question 41

Describe double helix

Answer 41

DNA molecule twisted into a double helix
Sugar phosphate (outside)
Base paies(inside)

Question 42

What enzyme is responsible for replication?

Answer 42

DNA polymerase

Question 43

What does dna polymerase need to start replication process?

Answer 43

Primers.

Question 44

What’s a primer?

Answer 44

Short strand of nucleotides which binds the 3’ of the dna strand allowing dna polymerase to add dna nucleotides.

Question 45

What does dna polymerase do?

Answer 45

Adds nucleotides in 1 direction,
Resulting in the leading strand being replicated continuously and the lagging strand replicated in fragments.

Question 46

What is ligase?

Answer 46

And enzyme that joins dna fragments together.

Question 47

Diploid cells have how many pairs of homologous chromosomes?

Answer 47

23