Stem cells to pg 136

Question 1

How do these pluripotent stem cells become specialsed

Answer 1

Genes are switched on and expressed causeing transcription, producing mRNA at gene. Then its translated in ribosomes , protein is modified and from their, function

Question 2

What is Totipotent

Answer 2

Potential to develop into a total individual and can produce all extraembroyonic cells like placenta

Question 3

Explain how groups of specilised cells produce the same etc. enzyme

Answer 3

Chemical hormone signals a gene to be activated or deactivated and all cells receive the same stimulus and are activated.
This causes mRNA to be produced and translation to produce proteins. Protein is modified and structure and function is determined

Question 4

What is multipotenent cell

Answer 4

Stem cells that can differiate into a limited number of specialized cells

Question 5

What does pluripotent cells

Answer 5

Can produce all specilised cells but not embroyonic

Question 6

How does a fertilized egg become foeutus, made up of specilaised cells

Answer 6

Mitosis cell divison occurs and form an embryo made up of totipotent cells called blastocyst

• Differentiation of these cells occurs as they multiply to form pluripotent cells
• Further cell differentiation occurs to produce specialised cells

Question 7

How can bone marrow be used to treat lukemeia

Answer 7

Bone marrow contains adult stem cells that divide
and differentiate to replace red blood cells and white blood cells
- Someone with leukaemia has damaged blood/bone marrow cells

Question 8

How can gene expression cause organism to produce specilised cells

Answer 8

under certain conditions some genes are activated while others are deactivated

• mRNA is only transcribed from active genes - this mRNA is then translated in the ribosomes into proteins
• these proteins determine cells shape a function -Interaction on the cells via specific proteins causes the cells to become differentiated.

Question 9

How can totipotent cells be used in plant culture

Answer 9

Totipotent cell is taken from a plant and placed in a growth medium containing nutrients and growth factors. - Stem cell will grow into unspecialised cells - Growth factors used

Question 10

Where are totipotent cells found in the plants

Answer 10

roots and shoots

Question 11

What are the ethnical issues with stem cells

Answer 11

stem cell use involves embryos, which have the potential to develop into a foetus

• Belief that each embryo has a right to life
• Stem cell research creates many embryos that are destroyed without any stem cells being taken (waste)

Question 12

What the difference between adult and embroyonic stem cells

Answer 12

Adult: - Can be obtained from body tissue/ easy to obtain
Embryonic:
- Created in a laboratory
- Have the capacity to develop into any specialised cell