Unit 8

Question 1

What is a gene mutation

Answer 1

• a change in the base sequence of a gene, which may result in a different amino acid sequence.

Question 2

Types of mutations

Answer 2

additiom
deletion
duplication
substitution
inversion

Question 3

which mutations cause frame shifts

Answer 3

addition
deletion
duplication

Question 4

what is a transcriptional factor

Answer 4

a protein that binds to a genes promoter, activating tramscription

Question 5

how do tf’s work

Answer 5

,ove from cytoplasm to nucleus where DNA is

Question 6

what is a promoter region

Answer 6

region upstream of the gene that controls its activity

Question 7

oestrogen uses

Answer 7

sperm production, functions in cardiovascular system, bone remodelling, CNS

Question 8

what os epigenetics

Answer 8

changing of genetic activity without changing the genetic code, influenced by lifestyle and the environment

Question 9

how can RNA polymerase attachment be inhibited

Answer 9

• dna being so tightly coiled around its histone so tf’s and rnap cannot attach
• methyl groups (ch3) added to bases to prevent tf attachment

Question 10

acetylation of histones

Answer 10

• adding acetyl groups to histone tail causing it to become negatively charged
• decreases attraction of histone to dna phosphate
• promoter upstream more accessible to tf’s

Question 11

effect of acetylation

Answer 11

increased acetylation = increased transcription
decreased acetylation = decreased transcription

Question 12

methylation of dna

Answer 12

• addition of methyl group in cytosine base
• inhibits transcription by methylation of CpG site
  1) prevents binding of tf to promoter
  2) attracts proteins that induce decreased acetylation

Question 13

what is an epigenome

Answer 13

all of the tags on our dna which are chemicals that bind to histones and dna

Question 14

tumour suppressor gene function

Answer 14

codes for regulatory proteins that slow the cell cycle down, preventing unregulated growth

Question 15

proto-oncogene function

Answer 15

codes for regulatory proteins that drive the cell cycle forward, promoting cell division, growth and development

Question 16

features of benign tumours

Answer 16

non cancerous
cannot spread
capsule
non invasive
slow growing

Question 17

malignant tumour features

Answer 17

cancerous
spread via blood
uncontrolled division
invasive
undifferentiated

Question 18

what is a circulating tumour cell

Answer 18

cancer cells escape from primary tumour and circulate in bloodstream
ctc’s exit the bloodstream, enter other organs and grow into new tumours

Question 19

how does mutated dna lead to cancer

Answer 19

1) dna altered by mutation changes the base sequence of a
2) proto-oncogene which leads to overexpression
OR
2) tumour suppressor gene causing primary structure to become altered