controlling gene expression

Question 1

stem cells

Answer 1

undifferentiated cells that can continually divide and become specialised

Question 2

totipotent stem cell

Answer 2

can differentiate into any body cell
occur for a limited time in early mammalian embryos

Question 3

pluripotent stem cell

Answer 3

can differentiate into almost any body cell
occur in embryos

Question 4

multipotent stem cell

Answer 4

can differentiate into a limited number of cells
found in mature mammals

Question 5

unipotent stem cells

Answer 5

can differentiate into one type of cell
found in mature mammals

Question 6

induced pluripotent stem cell

Answer 6

produced from adult somatic cells
using protein transcriptional factors overcomes ethical issues of using embryonic stem cells

Question 7

transcriptional factor

Answer 7

proteins that can bind to different base sequences on DNA
initiate transcription of genes

Question 8

what is a vector

Answer 8

a DNA molecule used as a vehicle to carry a DNA fragment

Question 9

acetylation of histone

Answer 9

decreased acetylation inhibits transcription
removing acetyl groups makes the histones more positive
this attracts the negative phosphate group on DNA
making it harder for transcriptional factors to bind

Question 10

RNA interference

Answer 10

inhibition of the translation of mRNA
the mRNA gets destroyed so it cannot be translated

Question 11

siRNA

Answer 11

small interfering RNA
destroys mRNA molecule to prevent translation