Notatki Danniego 9

Question 1

Linear relationship X ray dose x % mutations

Answer 1

• More X-Ray dose, more mutations
• Very low levels – damage is repairable

Procedure dose (mSv) Time period equivalent from natural background dose
Chest X-Ray 0.02 2.4 days
Skull X-Ray 0.1 12 days
Barium enema 8 2.7 years
CT abdomen 8 2.7 years

Breast CT scans were causing cancer whilst checking for it – was cancelled

Question 2

Zihaled radar

Answer 2

55% of average radiation exposure e.g 7% cosmic
Av- Average person
Av Uk Av Cornwall av nuclear worker freq flyer
2.5 7.8 4.5 2.9

Question 3

A lot of radom in air in Cornwall – hence much higher average radiation

Answer 3

Low doses of radiation could actually reduce cancer risk

- Hornesis (?)

Question 4

UV light causes inappropriate binding of DNA

Answer 4

• Thymine dimers
  - > causes Thymine to bind to another thymine
• Mutation repair of thymine dimers with excision enzymes (?)
• Xeroderma pigmentation (?)
• > lack of excision repair enzyme
• > genetic disorder
• Radiomimetic burns
• -> somatic mutations (burns) of skin under high energy radiation

Question 5

Anes test

Answer 5

Experimental sample -> Agar plate lacking histidine lots of samples present
Rat liver extract +
suspected mutagen

Histidine-dependent salmonella Incubation

control -> agar plate lacking histidine not many present

Question 6

Chemical mutations

Answer 6

• Things that tend to cause powerful mutations are more rare
  - > lettuce relative risk 0.04%
  - > Makes carcinogens to combat inserts feding on it (?) – Carffeic acid -> in a lot of foods
• Genome seems to change more than originally thought
  - > more fluid than stable
  - > many mutations
• 80% of mutations in offspring come from father
  - > wary in which germ cell are made
  - > the older the male, the more replications each sperm has been through
  - > higher chance of mutation leter in lige
• Telomeres are repeated sections of DNA that protect chromosomes when replicating
  - > Telomerase puts telomeres back together in babies
  - > Length reduces with age
  - > De(?) patients on average have shorter telomeres

Question 7

Natural selection

Answer 7

Descend with modification; Genetics plus time

Question 8

HIV - RNA retrovirus

Answer 8

• > 1/3 of people in Botswana ISA so on
  - > can see its evolution by sequencing it’s RNA
  - > large, quick diversification (?), resistance to drugs
  - > from West Africa
• Can estimate origin of HIV from divergence of recent strains
  - > ~ estimates that virus began to spread around 1910-1930
  - > Belgian colonists in the Congo (?)
  - > Bean around longer but no transmission/movement
• Simian immunodeficiency virus (SIV) in apes
  - > HIV evolved from this
  - > only causes mild symptoms in apes
• Many (?) juman DNA compared to chimps - 95% similar
  - > no fonges (?) still have cominos (?)
  - > same o. of hair follicles but no hair, less Keratin
  - > deletion in human sarcomanic myosin (?), not as much

Ys surface area of intestinces/ fewer digestion enzymes

Question 9

Humans are the only animals that cannot survive on only raw food!

Answer 9

k

Question 10

Humans are the only primates that don’t have spines on p (?)

Answer 10

-> deleted genes

Question 11

Humans are least varied primate from each other

Answer 11

• > physically speaking

- > e.g. (?) and east chimps have higher diversity than any 2 humans

Question 12

Humans have a very high number of cortical neurons

Answer 12

-> 12500 million

Question 13

Humans are only organism (?) that can speak

Answer 13

-> People with natural dyspression (?) show similar deletions for brain language genes as other primates lacking genes