stem cells

Question 1

what are the main features of a stem cell?

Answer 1

-undifferentiated, not specialised
-can express all genes
-can divide by mitosis
-pluripotent/ able to differentiate into any cell type

Question 2

what are the two things that stem cells can do?

why do they do it?

Answer 2

1) self renewal by mitosis= identical, maintaining a supply of stem cells

2) differentiation- replacing damaged or destroyed cells

Question 3

name the two types of stem cells found in humans

Answer 3

1) embryonic= totipotent and pluripotent

2) adults/ tissue stem cells = multipotent

Question 4

what are totipotent cells

what are pluripotent cells

Answer 4

totipotent= can make all cell types, is a zygote or early embryo cell

pluripotent= capable of producing all cells derived from a particular germ layer; ectoderm, endoderm, mesoderm

Question 5

what are multipotent cells

what are unipotent cells

Answer 5

multipotent- can make a restricted range of related cell types e.g haemopoietic stem cells ; red and white blood cells and platelets

unipotent- able to make one cell type e.g muscle stem cells= muscle tissue

Question 6

list examples of what stem cells can be used for and explain

Answer 6

-drug research = develop human tissue for testing instead of animal testing

-developmental biology = to understand how cells grow and mature and act during diseases

-transplants = bone marrow transplant to treat leukemia

-regenerative medicine = constructing specific organs

-repairing damaged tissue/ replacing lost tissue = nerve cells to treat neurodegenerative disease like Parkinson’s

Question 7

what are against arguments for stem cells

Answer 7

-unethical
-religious
-embryonic stem cells are unstable and can cause tumours

Question 8

what is an iPS cell

what are their advantages

Answer 8

-induced pluripotent stem cell, differentiated cells have been reprogrammed to become undifferentiated by switching on certain key genes

-not rejected/ don’t need imunosurpresent drugs