Causes And Effects Of Mutations

Question 1

How is variation classified

Answer 1

• large or small
• common or rare
• pathogenic or nonpathogenic

Question 2

What is an mutation

Answer 2

An alteration in the genetic material that gives harm

Question 3

What is polymorphism

Answer 3

Non harmful

Sequence changes that has no impact

Question 4

Common type of polymorphism

Answer 4

Single nucleotide polymorphism

Question 5

What is single nucleotide polymorphism

Answer 5

When only one nucleotide changes but has no impact

Question 6

How do we examine bases of dna

Answer 6

DNA sequencing

Question 7

How do examine large blocks of dna

Answer 7

FISH

Microarray analysis

Question 8

How do we examine chromosome

Answer 8

Light microscope by karyotypes

Question 9

How do mutation occur

Answer 9

• cell division

- from intrinsic and extrinsic attack on DNA

Question 10

How does cell division cause mutation

Answer 10

• during S PHASE of dna replication
• non-disjunction
• crossing over

Question 11

Mitotic cells give mutation

Answer 11

• dna replication : new mutation

- Anaomlies of chromosome number by non-disjunction

Question 12

What is the difference between somatic and germline mutation

Answer 12

Somatic only the individual is affected

Germ line can affect offspring

Question 13

What are the endogenous attacks to cause mutation

Answer 13

• depurination
• deamination
• reactive oxygen
• methylation of cytosine

Question 14

What is depurination

Answer 14

Spontaneous link between purine base and sugar

Question 15

What is deamination

Answer 15

Cytosine deaminates to uracil

Question 16

What does reactive oxygen do

Answer 16

Attack Purine or pyrimidine rings

Question 17

What is methylation of cytosine

Answer 17

Deamination of 5methylcytosine to thymine

Question 18

What are extracellular agents that cause dna damage

Answer 18

• uv
• environmental chemical
• ionizing radiation

Question 19

How does uv cause dna damage

Answer 19

Cross link adjacent thymine to form a dimer

Question 20

How does environmental chemical cause dna damage

Answer 20

Dna breaks

Question 21

How does ionizing radiation cause dna damage

Answer 21

Breaks dna

Question 22

How does the cell cycle prevent mutation

Answer 22

By checkpoints

Question 23

What occurs in dna replication to prevent replication errors

Answer 23

DNA polymerase proofread the strand and correct it’s wrong

Question 24

How is thymine diners corrected

Answer 24

DNA mismatch repair proteins remove the dna strand
The gap of removed dna is made again by DNA polymerase
Joined back by ligase

Question 25

How do you correct damage do ionizing radiation and reactive oxygen species

Answer 25

The DNA is broken

Repaired by homologous dna pairs

Question 26

What is end joining broken ends

Answer 26

When dna damage is repaired as a result of ionisation and oxygen species bu ends up with deletion of nucleotide at repair site

Question 27

What are the types of mutation affecting the coding sequence of a protein

Answer 27

Missense
Nonsense
Framshift
Duplication
Deletion
Insertion

Question 28

What is a silent mutation

Answer 28

When the mutation results in the same amino acid due to genetic code being redundant

Question 29

What is missense mutation

Answer 29

Change of an amino acid

Question 30

What is nonsense mutation

Answer 30

A stop codon is introduced so a protein does not form

Question 31

What happens when there is a splice-site mutation

Answer 31

Extrons may be spliced out to give an altered protein

Question 32

What type of disorder does triplet repeats give

Answer 32

Dominant inherited disease if it’s above the upper limits