Cells Diffentiation

Question 1

Cell Differentiation

Answer 1

All body cells the same DNA, yet differ and function and shape

Question 2

Cell Differentiation (2)

Answer 2

1) Process by which a cell becomes different from its parent or sister cell
2) Differentiation = different gene expression

Question 3

Differentiation in Early Development (2)

Answer 3

1) After fertilization, zygotes begin to divide up to 16 or 32 cells into a ball lol
2) After 8 -cell stages, cells are exposed to different enviroments inside versus outside the ball

Question 4

Cell Differentiation - Cloning

Answer 4

Can occur by embryo splitting 8 cell stage because cells are not yet differentiated

Question 5

How early Differentiation might occur (2)

Answer 5

1) before the 8 cell stage, all cells are exposed to the same environment and thus equal
2) After 8, typically 16 a cell at the surface will be exposed differently than a cell in the centre

Question 6

Differentiation Later in Development (2)

Answer 6

1) Developmental history of earlier cells & local environment
2) Genes are turned on and off at various staged of development

Question 7

What do you call genes that are turned on

Answer 7

unwinding of chromatin

Question 8

What do you call genes that are turned off

Answer 8

Closing of Chromatin

Question 9

When are cells differentiated? (2)

Answer 9

1) After 16 cell stages (after the surface is exposed differently than a cell in the centre)
2) Blastocyst

Question 10

When are genes unwound (turned on, active) and wound (turned off and not active) ?

Answer 10

During differential is the key moment of gene expression and the unwinding of chromatin and the closing of other chromatin

Question 11

What does Reproductive Cloning require? (2)

Answer 11

1) Embryo splitting *agriculture

2) Somatic Cell Nuclear Transfer * Dolly

Question 12

Reproductive cloning

Answer 12

Producing a copy of an entire organism - Dolly

Question 13

Producing Identical Offsprings: Embryo Splitting (3)

Answer 13

1) Egg is divided into vitro, and allowed to divide to the eight cell stage (vitro =refers to the technique of performing a given procedure in a controlled environment outside of a living organism)
2) Cell are separated and each implanted into different surrogates (mothers)
3) EIGHT identical offsprings not related to surrgate mother

Question 14

Cloning by Embryo summarized (4)

Answer 14

1) Egg + sperm
2) Fertilize vitro
3) Let it go to the 8 cell stage (all identical)
4) Impregnate 8 mothers / surrogates
5) 8 identical copies

Question 15

Somatic Cell Nuclear Transfer Produces a Clone of an Adult - Somatic Cell

Answer 15

1) Any cell other than a haploid

2) Each somatic cell has a full diploid set of chromosomes

Question 16

Somatic Cell Nuclear Transfer Produces a Clone of an Adult - Somatic Cell - Diploid cell importance

Answer 16

1) Note that these cell are DIFFERENTIATED unlike cloning by embryo

Question 17

Somatic Cell Nuclear Transfer Produces a Clone of an Adult - Procedure (4)

Answer 17

1) Somatic Cell NUCLEUS is inserted into the UNUCLEATED fertilized egg
2) Implanted into surrogate mother
3) Offspring identical to the nuclear donor animal none from mother

Question 18

Somatic Cell Nuclear Transfer Produces a Clone of an Adult - After the nucleus is applied to the egg how is activate?

Answer 18

Electrical current is applied to fuse cells

Question 19

Somatic Cell Nuclear Transfer Produces a Clone of an Adult - Is there mitochondrial DNA in the egg?

Answer 19

Yes

Question 20

Somatic Cell Nuclear Transfer Produces a Clone of an Adult - Does the egg reprogram the donated chromatin

Answer 20

Yes

Question 21

Reprogramming during normal development and cloning

Answer 21

The reprogramming of epigenetic becomes essential

Question 22

Reprogramming during normal development and cloning - Define epigenetics

Answer 22

non- coding hereditary information

Question 23

The reprogramming of epigenetic becomes essential (3) **

Answer 23

1) The donor nucleus needs to be reprogrammed in cloning
2) The sperm and egg need to be reprogrammed during fertilization
3) Epigenetic helps define the genes that are turned off, by providing signal of tighter chromatins

Question 24

What is composed of a chromosome? (3)

Answer 24

1) Chromatin
2) Histones
3) DNA

Question 25

How is Chromatin, Histones, DNA [chromosome] reprogrammed by nuclear transfer? (4)

Answer 25

1) By the removal and additional of chemical modifications
2) No changes to DNA
3) Histone modification
4) DNA methylation

Question 26

Therapeutic Cloning

Answer 26

Creating Tissues and Organs

Question 27

Therapeutic Cloning: Creating Tissues and Organs (3)

Answer 27

1) Cloning human to treat patients
2) Ideally removing a single cell from patient and transforming it to develop and differentiate into what is needed
3) REPROGRAMMING IS KEY

Question 28

Therapeutic Cloning: Creating Tissues and Organs: (4)

Answer 28

1) Somatic Cell Biopsy
2) Enucleated Oocyte + Nuclear transfer (somatic cell)
3) Embryo
4) Stem cells from embryo - produce all cells in body