Lecture 32: Cloning, Stem Cells and Gene Therapy

Question 1

Cells become more ______ and less ______ during development.

Answer 1

• Specialised

- Felxible

Question 2

What is the trophectoderm?

Answer 2

• Placenta

Question 3

Embryo begins as a small number of naive, ________ cells.

Answer 3

• Totipotent

Question 4

Embryonic stem cells can give rise to all cell types except trophectoderm, these are known as _____ cells.

Answer 4

• Pluripotent

Question 5

Progressive restriction of cell fate until terminally differentiated, and can only give rise to same type of cell. Except _____ and ______ cells.

Answer 5

• Stem
• Germ
• (Eggs & Sperm)

Question 6

In Embryonic cells, at the beginning, control genes (myoD) and all other muscle specific genes are turned….

Answer 6

• Off

Question 7

When myoD proteins in an embryonic cells are turned on, and other muscle specific genes are turned off, it’s getting ready to… (Determination)

Answer 7

• Become a muscle cell

Question 8

When myoD proteins in an embryonic cells are turned on, and other muscle specific genes are turned on, it’s become a… (Differentiation)

Answer 8

• Muscle cell

Question 9

Features of stem cells:

Answer 9

• Can divide without limit
• Undifferentiated
• Can divide and maintain their population

Question 10

The difference between adult stem cells and embryonic stem cells:

Answer 10

• Embryonic stem cells = totipotent and give rise to all types of blood cells
• Adult stem cells, come rom bone marrow and mostly give rise to blood cells

Question 11

Stem cells are important for tissues such as….

Answer 11

• Blood and skin

Question 12

Plasticity:

Answer 12

• The ability of stem cells from one adult tissue to generate differentiated cell types of another tissue

Question 13

Bone marrow also contains mesenchymal stem cells which can give rise to…

Answer 13

• Blood cells and some cartilage cells

Question 14

Umbilical cord stem cells are often…however are not _______ but are immature…….

Answer 14

• Banked (kept frozen)
• Pluripotent
• Blood stem cells

Question 15

Induced pluripotent stem (iPS) cells are…

Answer 15

• Made by reprogramming adult cells

Question 16

Gene therapy is best applied to…and can be achieved using..

Answer 16

• Stem cells
• Because they will keep dividing and pass on corrected gene
• Retroviruses

Question 17

Early embryo =
Differentiated cell =
Stem cells =

Answer 17

• All or most cell types
• One cell type
• Some cell types and more stem cells

Question 18

How was Dolly the Sheep cloned?

Answer 18

• Forced donor mammary cells into G0 ‘resting’ phase of the cell cycle
• Delivered pulses of electric current to the egg
• Nuclear genome from nuclear donor
• She’s identical to the mammary cell donor but the mitochondrial genome comes from the egg donor
• No DNA from surrogate mother

Question 19

Why clone humans?

Answer 19

• Dolly is an example of reproductive humans
• Therapeutic cloning involves the creation of “personalised” embryonic stem cells
• A donor nucleus is transferred into an enucleated zygote as for reproductive cloning
• The embryo is cultured until the blastocyst stage
• Cultured under various conditions to make cell types to order
• iPS cells from patients with genetic disease can also be used to make cells or tissues for drug testing
• Use minilungs for drug testing, so you don’t have to use humans