Gene Expression-Topic 8A Flashcards

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

When might gene mutations occur?

A

During DNA replication

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

What is a mutation?

A

A change to the base (nucleotide) sequence of DNA

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

What is Substitution?

A

One or more bases swapper e.g.

AT G C becomes AT T C

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

What is Addition/ Insertion

A

One or more bases added so ACTG becomes ACATG

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

What is Deletion?

A

One or more bases removed so

ACTG becomes CTG

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

What is Duplication?

A

One or more bases repeated so ATGCCT becomes ATGCCCCT

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

What is Inversion?

A

A sequence of bases is reversed e.g A TGCC T becomes A CCGT T

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

What is Translocation? (type of mutation)

A

A sequence of bases is moved from one location in the genome to another (within same OR different chromosome)

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

How is the rate of mutation increased?

A

Mutagenic agents

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

Gene mutations occur ………

A

spontaneously

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

Which types of mutations cause a frameshift?

A

Additions, duplications and deletions

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

What is a frame shift?

A

a shift in the base triplets that mean that the triplet code is read in a different way.

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

What is epigenetics?

A

Heritable changes in gene function caused by changes in environment without change to base sequence of DNA

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

Ways that transcription is inhibited by:

A

increased methylation

decreased acetylation

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

Describe the effect of decreased acetylation of histones on the transcription of genes they are associated with. [3]

A

Decreased acetylation = more highly condensed DNA-Histone complex
therefore transcription factor cannot access DNA
and DNA can’t be transcribed.

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

What are totipotent cells?

A

Early embryonic stem cell that can divide and produce any type of body cell.

17
Q

What are pluripotent cells?

A

Pluripotent stem cells can divide in unlimited numbers and can be used in treating human disorders

18
Q

What are multipotent cells?

A

stem cells found in mature mammals and can divide to form a limited number of different cell types.

19
Q

What are unipotent cells?

A

stem cells found in mature mammals and can divide to form a limited number of different cell types.

20
Q

What are induced pluripotent cells? (iPS)

A

Induced pluripotent stem cells (iPS cells) can be produced from adult somatic cells using protein transcription factors

21
Q

Example of unipotent cells dividing into

A

cardiomyocytes (cells of heart)

22
Q

Explain how an activated oestrogen

receptor affects the target cell. [2]

A

Transcription factor binds to promoter region which stimulates RNA polymerase
which increases transcription

23
Q

Oestrogen only affects target cells. Explain why oestrogen does not affect other cells in the body. [1]

A

As only oestrogen has those specific receptors

24
Q

Describe how translation can epigenetically control gene expression ?

A

Double stranded RNA broken by enzyme into siRNA
1 of these strands now combines with enzyme
siRNA strand pairs up with complementary bases on mRNA strand.
The enzyme cuts the mRNA into smaller sections

25
Q

How does oestrogen enter the cytoplasm where transcriptional factor is?

A

Diffuses through the phospholipid bilayer as it is lipid soluble

26
Q

Name a transcriptional factor that initiates transcription

A

Oestrogen

27
Q

What is transcription of genes controlled by?

A

Transcription factors

28
Q

What is a suppressor?

A

Transcription factors that inhibit gene expression

29
Q

Transcription factors move from the ….. to the …..

A

cytoplasm to the nucleus

30
Q

How do activators work?

A

Help RNA polymerase bind to the start of a target gene, and activate transcription.

31
Q

How do suppressors work?

A

Bind to the start of target gene preventing RNA polymerase from binding, stopping transcription.