8.1 Gene Expression

Question 1

stem cell

Answer 1

an undifferentiated cell which can specalise into other cells

Question 2

totipotent stem cell

Answer 2

can differentiate into ALL cells
found within first 3 divisons of fertilisation

Question 3

pluripotent stem cells

Answer 3

can differentiate into MOST cells
found in embryonic stem cells

Question 4

multipotent stem cells

Answer 4

can differentiate into SOME cells
eg adult stem cells in bone marrow

Question 5

unipotent stem cells

Answer 5

can differentiate into ONE type of cell
found in adults

Question 6

epigenetics

Answer 6

heritable changes in gene function without changes to the base sequence of DNA

Question 7

transcription factors

Answer 7

proteins which when activated bind to the promoter region of a gene stimulating RNA polymerase to transcribe the target gene
can control rate of production

Question 8

duplication mutation (chromosomal)

Answer 8

a section of a chromosome is copied so there is two versions

Question 9

inversion mutation (chromosomal)

Answer 9

two sections of the chromosome are switched

Question 10

explain how increased methylation could lead to cancer

Answer 10

methyl group could be added to tumor suppressor gene
this inhibits the transcription of tumor surpressor gene leading to uncontrolled cell divison

Question 11

one way in which benign tumours differ from malignant tumors

Answer 11

benign tumours cannot spread to other parts of body malignant can

Question 12

genome

Answer 12

all the genes of an organism

Question 13

oestrogen only affects target cells explain why oestrogen does not affect other cells in the body.

Answer 13

other cells do not have oestrgoen receptors only target cells do