key area 1.4 - cellular differentiation

Question 1

cellular differentiation

Answer 1

• process by which an unspecialised cell becomes specialised to carry out a specific function in the body
• cell expresses certain genes to produce characteristics for that type of cell

Question 2

selective gene expression

Answer 2

• genes can be switched on or off within a cell to save energy by not producing proteins that are not needed

Question 3

meristems

Answer 3

a group of unspecialised plant cells capable of dividing / self renewing and differentiating throughout a plants life

Question 4

embryonic stem cells

Answer 4

• all genes have potential to be turned on
• can differentiate into any type of cell found in the human body
• pluripotent

Question 5

adult / tissue stem cells

Answer 5

• type of cell capable of differentiating into all types of cell found in a particular tissue type
• some genes already switched off
• multipotent
• replaces damaged cells to help repair and maintain the body

Question 6

specialised

Answer 6

• cell has become differentiated and only expresses genes for proteins specific to that type of cell

Question 7

therapeutic uses of stem cells

Answer 7

• repair of damaged or diseased tissue or organs
• skin grafts for burn victims
• corneal repair
• tissue cells in bone marrow can help treat blood cancer
• in future hope to help disease such as alzheimer’s or parkinson’s

Question 8

research uses of stem cells

Answer 8

• provides information on how cellular processes work such as cell growth, differentiation and gene regulation. this can lead to better understanding of diseases such as cancer
• model cells for drug testing

Question 9

ethical issues of embryonic stem cells

Answer 9

• some people believe using embryonic stem cells is wrong as people feel that because embryos are potential humans that they are being denied the opportunity to live a life due to getting the stem cells