Mutations, Gene expression and Cancer

Question 1

what is the genetic code described as

Answer 1

universal
degenerate
non-overlapping

Question 2

what does universal mean

Answer 2

same 3 bases on mRNA codon for the same amino acids in all organisms

Question 3

what does non-overlapping mean

Answer 3

the ribosome reads each base only once in the codons

Question 4

what does degenerate mean

Answer 4

more than one triplet codes for an amino acids

Question 5

what is the term for 3 bases on DNA

Answer 5

triplet

Question 6

what is the term for 3 bases on tRNA

Answer 6

anticodon

Question 7

types of mutations

Answer 7

substitution
addition
deletion
inversion
translocation
(chromosomal mutations)
duplication mutations

Question 8

what are the types of mutagenic agents

Answer 8

high energy ionising radiation
DNA reactive chemicals
Biological agents

Question 9

types of stem cells

Answer 9

Totipotent
Pluripotent
Multipotent
Unipotent

Question 10

what is the process of which cells become specialised

Answer 10

cell differentiation

Question 11

where are totipotent cells found

Answer 11

zygote and early embryo (upto 8 cell stage)

Question 12

where are pluripotent cells found

Answer 12

embryonic and fetal stem cells

Question 13

where are multipotent found

Answer 13

adult stem cells

Question 14

where are unipotent cells found

Answer 14

used in the formation of single type of cells eg. cardiomyocytes

Question 15

how many cells can totipotent cells differentiate into

Answer 15

any type of cell

Question 16

how many cells can pluripotent cells differentiate into

Answer 16

most types of cells

Question 17

how many cells can multipotent cells differentiate into

Answer 17

some types of cells

Question 18

how many cells can unipotent cells differentiate into

Answer 18

only one type of cell
eg. heart stem cells differentiate into cardiomyocytes

Question 19

What is a promoter region

Answer 19

one or more base sequences found upstream of a gene that control the expression of that gene

Question 20

what is a transcription factor

Answer 20

proteins which when activated, bind to the promoter region of a gene stimulating RNA polymerase to begin transcription the target gene

Question 21

why does RNA interference occur

Answer 21

-protein synthesis uses large amounts of ATP
-overproduction of a specific protein is a waste of valuable ATP
-if a cell has synthesised enough of a specific protein

Question 22

two types of interfering RNA

Answer 22

microRNA
small interfering RNA

Question 23

How does interfering RNA work

Answer 23

inheritable changes in gene expression without changes to their DNA base sequence

Question 24

Inheritable changes are caused by changes in the gene’s environment that inhibit transcription by:

Answer 24

-increased methylation of DNA
-decreased acetylation of histones

Question 25

process of methylation of DNA

Answer 25

CH3 is linked to CG bases on the promoter region upstream of the gene

Question 26

process of interfering RNA

Answer 26

microRNA and siRNA are complementary to RNA degenerates the RNA translation is reduced

Question 27

process of acetylation of histones

Answer 27

-acetyl groups on histone tails -histones are not tightly packed -promoter region is left exposed