D1.3: Gene Mutation

Question 1

Post-transcription

Answer 1

Mythlene cap + poly-A tail

Question 2

Define proteosomes

Answer 2

Total protein material used in cell
- Recycles unused amino acid

Question 3

Post-translation

Answer 3

what happens to polypeptides after translation

Question 4

Describe the characteristics of the genetic code

Answer 4

• 64 codons
• universal
• 20 a.a.

Question 5

Why do some mutations not result to structural changes?

Answer 5

Because of silent mutations

Question 6

Give the two types of mutations

Answer 6

Base substitution and frameshift mutation

Question 7

Define base substitution

Answer 7

aka point mutations
- substitution of 1 nitro base

Question 8

Define gene mutation

Answer 8

permanent change in gene seq of DNA

Question 9

Outline the three types of base substitution

Answer 9

• silent mutation: no noticeable effect on protein
• missense: maybe 1 change in aa
• nonsense mutation: change to early stop codon

Question 10

Outline the two types of missense

Answer 10

• conservative - results in a functional protein
• non-conservative - now not functional

Question 11

Define allele

Answer 11

versions of a gene (e.g. blue and brown eye color)

Question 12

Define frameshift mutation

Answer 12

• occurs whentheres an insertion or deletion of a base
• affects how the genetic sequence is read

Question 13

Which type of cell passes on mutations?

Answer 13

Gametes

Question 14

How many mutations are there per generation

Answer 14

~100-200

Question 15

Cause of sickle cell anemia

Answer 15

base substitution to the 6th codon for the beta chain of hemoglobin
-> for memory: CTC (velinxi) -> CAC (that one bruno mars dragon meme — jump in the cac)

Question 16

Sickle cell consequences

Answer 16

• formation of fibrous haemoglobulin turns blood cell into sickle shape
• destroyed more rapidly -> low RBC count
• may form clots within capillaries
• shape not denatured but changed
• can return to high oxygen normal shape

Question 17

Outline the types of mutagens

Answer 17

• physical - forms of radioation
• chemical - chemical substances (reactive oxygen series, metals like arsenic..)
• biological - some viruses and certain bacteria

Question 18

Define block mutations

Answer 18

Changes to segments or a chromosome, resulting in large scale changes

Question 19

Define transposons

Answer 19

Mobile genetic elements that can change positions in the genome

Question 20

Outline the different types of block mutation

Answer 20

Question 21

Where can mutations occur?

Answer 21

Anywhere but some placed have a higher probability of mutating

Question 22

Why does mitochondrial DNA have a higher chance of mutation

Answer 22

Limited protection: Unlike nuclear DNA which is wrapped in a protective protein coat (histones), mtDNA is more exposed within the mitochondria. This lack of a shield makes it more susceptible to damage from ROS and other environmental factors.

Question 23

Why can mutations be beneficial, detrimental or neutral?

Answer 23

No pre-determined direction, random chance

Question 24

How does mutation act as a source of genetic variation?

Answer 24

Only source of new alleles in a population
- continuous variation and follow a normal distribution curve as the rate of change is gradual and cumulative
- ^ diversity ^ beneficial mutations via natural selection

Question 25

What are the classifications of mutations?

Answer 25

• Somatic
• Germ-line
  (depends in type of cell)

Question 26

Define somatic mutations

Answer 26

Occur in a single body cell and cannot be inherited
- only tissue of origin of mutated cell

Question 27

Germline mutations

Answer 27

occur in gametes and can be passed on to offspring
- affects every cell