Unit 1.4 Cellular differentiation

Question 1

What is a meristem?

Answer 1

A region in plants in which growth takes place
- meristems are where a group of unspecialised undifferentiated cells will divide to make more unspecialised and undifferentiated cells.

Question 2

What makes meristems different from other types of plant cells?

Answer 2

• Meristems are able to divide repeatedly (Self renew)
• Meristems are able to differentiate into different types of specialised plant cells.

Question 3

What are stem cells?

Answer 3

Unspecialised, and undifferentiated animal cells that are involved in the growth and repair of tissue.

Question 4

What does self renewal of stem cells refer to?

Answer 4

Stem cells are able to divide by mitosis without becoming specialised.

Question 5

What does the differentiation of stem cells refer to?

Answer 5

The ability of a stem cell to become a different type of cell with a more specialised function. This is due to certain genes being expressed while others are switched off.

Question 6

What is unique about Embryonic stem cells?

Answer 6

Embryonic stem cells can differentiate to become any type of cell, hence they are said to be pluripotent.

Question 7

what are the features of Tissue adult stem cells?

Answer 7

Tissue adult stem cells are undifferentiated cells that can divide in order to self renew and can only differentiate to become a few types of cells, hence they have a limited range of cells that they can become and are described by the term multi-potent. These stem cells are found in fully formed animals and are only capable of differentiating to become any cell in a group of tissues.

Question 8

What can stem cells be used for in the Lab?

Answer 8

• They provide research and can be used as model cells:
  *to investigate cell processes,
  *study the development of disease,
  *and test drugs and vaccines
• Therapeutic value, the repair of damaged or diseased organs or tissues

Question 9

What are some ethical considerations around the use of stem cells in research?

Answer 9

• Embryonic stem cells being removed from a blastocyst is the only way to obtain these pluripotent stem cells, however this requires the embryo to be destroyed.
• Embryonic stem cells are pluripotent and can be used to offer effective treatment of many diseases and injuries such as burns.

Question 10

What is cellular differentiation?

Answer 10

the process by which certain genes of a cells genotype will be expressed to produce proteins charateristic for that cell

Question 11

Give examples of the thereputic uses of stem cells?

Answer 11

• corneal repair
• the regeneration of damaged skin