Mutations Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

Define mutations?

A

Defined as heritable changes in DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define somatic mutations

A

Occur in somatic (body) cells.
Mutations is passed to daughter cells, but not sexually produced offspring.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define germline mutations

A

Occur in cells that prod gametes
Can be passed to next generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What 2 scales con mutations occur?

A

Point mutations affecting just 1 or very few bases
Chromosomal mutations: affecting whole sections of chromosome (potentially 1000’s bases )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are point mutations?t

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are silent mutations?

A

Have no effect on the protein because of the redundancy of genetic code

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define missense mutations?

A

Base substitutions results in amino acid substitution
E.g.)s ickle cell disease
Defected sickle-shaped red blood ou

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define nonsense mutations?

A

Base substitution results in a stop codon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define frame-shift mutation?

A

Single bases inserted or deleted → usually leadig to non-functional proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Types of chromosomal mutations?

A

Deletions
Duplications
Inversions
Translocation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define deletion

A

DNA molecule breaks at 2 points and 2 pieces rejoin leaving out DNA between break
Severe consequences unless it affects unnescemry genes or it missing genes are mashed by normal alleles on a homologous chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define dupli cation’s

A

Homologous chromosomes break in diff places and recombine with wrong patterns

May not be problem in original cell which still has 2 alleles for each gene but could cause problems in future generation as gametes formed by meiosis would pass on only one of these chrome comes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define inversions

A

Breaking and rejoining but A segment is flipped

May have no effect unless the break site happens in the middle of gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define translocation

A

Segment of DNA break of f and is inserted into another non-homologous chromosome
Meiosis can be prevented as chromosome pairing may be impossible.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define s spontaneous mutations?

A

No outside influence
Tautomerisation
A temporary change caused by migration of an atom within the molecule
A problem if this happens during DNA replication → this rare tauter binds with an A
Cytosine → common tauter
2.) de animation
Bases may change →spontaneous chemical changes remove AA
1 in 100 c would change in human lifetime if - not repaired
3.) DNA replication errors
Some escape detection and repair by proofreading ability of DNA polymerase
4.) non-disjunction in meiosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define induced mutation?

A

Due to an outside agent → a mutagen
Deamination
Chemicals such as nitrous acid (formed from nitrates)
Be laminated form of cytosine → uracil
2.) addition to bases
Benzopyrene → found in tobacco smoke adds a group to guanine and prevents base pairings
3.) ionising radiation
Ionising radiation con change bases break sugar phosphate bonds
4.) UV radiation is absorbed by thymine causing it to form covalent bonds with adjacent nucleotides

17
Q

What do mutations provide?

A

Often produce an organism less fit for the environment
Mutations con improve organisms adaptation to its environment or be come favourable as conditions change

18
Q

How does replication of gene expre’ssion in: prokaryotes takes place?

A

Usually a case of regulating transcription
RNA polymerase begins at a promoter where transaction is initiated
Selective gene transcriptions → a “descesion” is made about which genes will be transcribed

19
Q

What are the 2 types of gene expression?

A

Negative regulation
→ gene is normally transcribed ( usually” on”)
→ binding of a depressor protein prevents transcription
Positive regulation
→ gene is not normally transcribed ( usually “off”)
→ activator protein binds to stimulate transcription

20
Q

The lac open

A

?

21
Q

Try open

A
22
Q

Define Ind ucible system?

A

Control digestive /catabolic pathways
Turned Off when substrateis absent

23
Q

Define repressible system?

A

Control biosynthetic /anabolic pathways
(Turned off when productis present)