6.1-cellular bontrol Flashcards

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

what is a mutation?

A

random change to genetic material.

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

what is a gene mutation?

A

random change to DNA

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

what are mutations associated with mitotic division called?

A

somatic mutations

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

can mutations during mitosis be passed to offspring?

A

no

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

what might mutations during mitosis be associated with?

A

tumours

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

what are the 2 main classes of DNA mutation?

A

point mutation

indel

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

what do indel mutations cause?

A

frameshift

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

what are the 3 types of point mutation?

A

silent
missense
nonsense

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

what happens during a point mutation?

A

one base pair is substituted for another

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

what happens during a silent mutation?

A

point mutation changes base triplet but it still codes for the same amino acid.

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

what enables silent mutations to happen?

A

genetic code is degenerate: all amino acids (apart from methionine) have more than 1 base triplet code.

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

what is a missense mutation?

A

change in the base sequence that leads to a change in amino acid sequence in a protein.

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

what is an example of a disease caused by a missense mutation?

A

sickle cell anaemia

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

what causes sickle cell?

A

valine instead of glutamic acid added to b polypeptide chain.

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

what happens to the blood cells of someone with sickle cell?

A

deoxygenated haemoglobin crystallises in them, causing them to be sickle shaped, blocking capillaries and depriving tissues of o2.

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

what happens during nonsense mutations?

A

a point mutation alters a base triplet so it becomes a stop triplet.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what happens to the proteins that are results of nonsense mutations?

A

truncated and dysfunctional-likely degraded within cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is an example of a disease caused by a nonsense mutation?

A

Duchenne muscular dystrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is an example of a disease caused by deletions of bases?

A

thalassaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what happens during expanding triple nucleotide repeats?

A

in genes which contains a repeating triplet, the number of that triplet increases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what’s a disease caused by expanding triple nucleotide repeats?

A

huntingtons-repeat of CAG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is a disadvantage of having blue eyes?

A

in areas with high sun: could lead to lens cataracts

23
Q

what is an exon?

A

the coding,or expressed,region of dna

24
Q

what is an intron?

A

the non coding region of dna

25
Q

what is an operon?

A

a group of genes that function as a single transcription unit

26
Q

what is a transcription factor?

A

protein or short non-coding RNA that can combine with dna and inhibit or activate transcription of a gene.

27
Q

what is E.coli’s normal respiratory substrate?

A

glucose

28
Q

what does the lack of glucose and presence of lactose cause E.coli to produce?

A

lactose permease

b-galactosidase

29
Q

what does lactose permease do?

A

allows lactose to enter cell

30
Q

what does b-galactosidase do?

A

hydrolyses lactose to glucose and galactose

31
Q

in the lac operon what is lacO?

A

operator region

32
Q

in the lac operon what is lacZ?

A

structural gene that codes for b-galactosidase

33
Q

in the lac operon what is lacY?

A

structural gene that codes for lactose permease

34
Q

what happens at the promoter region (P)of the lac operon?

A

RNA polymerase binds to begin transcription of lacZ and lacY.

35
Q

what does the regulatory gene (I) code for in the lac operon?

A

a repressor protein, LacI

36
Q

what does the repressor protein do in the lac operon?

A

binds to the operator, preventing RNA polymerase from binding to the promoter region

37
Q

when lactose is present what happens to the LacI repressor protein?

A

molecules of glucose bind to it-its shape gets altered-it’s prevented from binding to the operator

38
Q

are introns and exons both transcribed?

A

yes

39
Q

what is primary mRNA?

A

mRNA with both introns and exons transcribed.

40
Q

what happens when primary mRNA is edited?

A

RNA introns are removed+ the remaining exons joined together (endonuclease enzyme may be involved in this process)

41
Q

how are many enzymes activated?

A

by being phosphorylated

42
Q

what is the homeobox sequence?

A

sequence of 180 base pairs found within genes involved in regulating patterns of anatomical development in animals, fungi and plants

43
Q

what are hox genes?

A

subset of homeobox genes found only in animals-involved in the formation of anatomical features in correct locations of body plan.

44
Q

what is a homeodomain sequence?

A

60 amino acid sequence within a protein coded for by the homeobox sequence.

45
Q

what does the homeodomain sequence do?

A

folds into a specific shape and binds to dna, regulating transcription of adjacent genes.

46
Q

what is the shape of a homeodomain containing protein?

A

HTH: two a helixes connected by a turn

47
Q

what is an enhancer region?

A

region that initiates or enhances transcription.

48
Q

what does it mean when a gene is conserved?

A

it has remained in an descendent species throughout evolutionary history.

49
Q

what is colinearity?

A

a phenomenon where the temporal and sequential order of the gene expressions corresponds to the sequential and temporal development of various body parts. (like the gene at the end codes for the tail)

50
Q

what can homeodomain proteins do in the nucleus?

A

switch on cascades of activation of other genes that promote mitosis, apoptosis, cell cycle regulation.

51
Q

what are hox genes regulated by?

A

other genes called gap genes and pair-rule genes

52
Q

what signal molecules are involved in stimulating apoptosis?

A

cytokines
hormones
growth factors
nitric oxide (NO)

53
Q

what are 2 examples of apoptosis being useful in humans?

A

causes separation of toes

removes ineffective or harmful t-lymphocytes when immune system is developing