Early Embryonic development and Cell differentiation

Question 1

What is embryonic differentiation?

Answer 1

process during which embryonic cells specialise and diverse tissue structures arse, each with a special function

Question 2

Types of stem cells

Answer 2

totipotent, pluripotent, multipotent

Question 3

Totipotent

Answer 3

can give rise to all cell typed found in the adult organism, including extraembryonic cells (eg. zygote)

Question 4

Pluripotent

Answer 4

can give rise to all 3 germ layers, but not extraembryonic cells (eg. inner cell mass)

Question 5

Multipotent

Answer 5

restricted number of different cell types

found in some tissues (eg. bone marrow can generate replacement cells but only of the same/similar type)

Question 6

Uses of adult stem cells

Answer 6

multipotent and scarce, therefore slow rate of cell division

can replace tissue that is damaged through disease/injury

Question 7

Uses of embryonic stem cells

Answer 7

pluripotent, can form almost any cell/tissue type

Question 8

How are embryonic stem cells obtained?

Answer 8

1. reproductive cloning - from embryos after IVF
2. therapeutic cloning/somatic nuclear transfer - nuclei from adult stem cells and introduce to enucleated oocytes, which are stimulated to differentiate into blastocysts, ESCs harvested

Question 9

Problems with reproductive cloning

Answer 9

immune rejection

ethics - cells come from viable embryos

Question 10

Advantages of therapeutic cloning

Answer 10

derived from host, therefore genetically compatible

more ethical