Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Principles > Genetics > Flashcards

Genetics Flashcards

1
Q

where is the information in DNA held?

A

it is held in the sequence of the bases which are held on a sugar phosphate backbone

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

Thymine pairs with

A

adenine

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

guanine pairs with

A

cytosine

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

DNA is wound into a chromosome by..?

A

Wrapping around histone proteins

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

what phase of the cell cycle does DNA replication happen?

A

S phase

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

why might DNA be damaged?

A

the DNA strand breaks, there is chemical cross linking or there is a mismatched base

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

how can DNA damage be fixed?

A

by repair mechanisms

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

What happens when there are defects in the repair mechanisms?

A

disease

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

during mitosis, one diploid parent cell turns into…

A

two identical diploid daughter cells

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

during meiosis, one diploid parent cell becomes…

A

4 haploid daughter cell (one of each chromosome to each cell)

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

when does meiosis occur?

A

in gamete formation

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

what is crossing over?

A

Crossing over is the exchange of genetic material between non-sister chromatids of homologous chromosomes during meiosis, which results in new allelic combinations in the daughter cells.

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

how does a gene go from DNA to mRNA

A

transcription and splicing

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

how does a gene go from mRNA to protein

A

translation

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

what is the amount of protein produced determined by? 4 answers

A
  • rate of transcription
  • rate of splicing to mRNA
  • half life of mRNA
  • rate of processing of polypeptide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what can 3 bases encode for?

A

1 amino acid or a stop

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

how is mRNA produced from DNA? Two steps

A

DNA is transcribed to pre mRNA and then pre mRNA is spliced to mRNA

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

what is polymorphism?

A

a variation in the human genome that has a population frequency greater than 1% or a variation that does not cause a disease in its own right

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

what is a mutation?

A

a gene change that causes a genetic disorder

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

why does variation happen?

A

DNA replication is not perfect

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

what three things allow a chromosome to be recognised?

A

banding pattern with specific stains, length and position of centromere

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

what arm on the chromosome doesn’t really matter?

A

the short arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is the balanced chromosome rearrangement?

A

all the chromosomal material is present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the unbalanced chromosome rearrangement?

A

extra or missing chromosomal material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

term for whole or missing chromosome ?

A

aneuploidy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

term for rearrangement of chromosomes?

A

translocation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

large chromosomal imbalance results in?

A

a higher chance of miscarriage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

notation for male down syndrome

A

47XY + 21

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

translocation that has a high chance of miscarriage

A

trisomy 14

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what is the name of the condition trisomy 18?

A

Edwards syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

notation for Edwards syndrome male

A

47 XY + 18

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

why is X chromosome aneuploidy better tolerated?

A

because of X inactivation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what is X inactivation?

A

the random process of one female X chromosome inactivating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

result of reciprocal translocations

A

50% will have normal chromosomes or balanced translocation but the other 50% will miscarriage or have a dysmorphic delayed child

35
Q

what do reciprocal translocations have to survive?

A

meiosis

36
Q

effects of large translocation

A

large risk of miscarriage and small risk of a dysmorphic delayed child

37
Q

effects of a small translocation

A

small risk of miscarriage but large risk in a having a dysmorphic delayed child

38
Q

how many bases is too small to see?

A

5 million

39
Q

cheapest quickest and most sensitive way to count chromosomes?

A

molecular techniques - no longer FISH

40
Q

newest test available for looking at chromosomes?

A

Array CGH

array genomic hybridisation

41
Q

benefits of array CGH

A

allows detection of any size chromosome imbalances

42
Q

what does array CGH not detect?

A

balanced rearrangements

43
Q

what could chromosome changes do?

A

activate an oncogene or delete a tumour suppressor

44
Q

what is an oncogene?

A

a gene which in certain circumstances can transform a cell into a tumour cell

45
Q

what type of analysis do you use to detect chromosome deletions/duplications for balanced rearrangements?

A

aCGH

46
Q

what is PCR?

A

a process that allows us to select a short stretch of the genome and amplify it

47
Q

how much of the genome is axons?

A

only 2-3%

48
Q

what does the rest of the genome do that isn’t an exon?

A

regulate genes, space genes out, insulate genes from promotors and add genes

49
Q

what carries genes?

A

chromsomes

50
Q

when can mutations arise during cell division?

A

at any point in the human life cycle

51
Q

a genetic change that contributes to cancer

A

somatic mosaicism for a chromosomal abnormality

52
Q

what does NGS stand for

A

Next generation sequencing

53
Q

what does NGS allow?

A

large scale sequencing cheaply- whole exam or whole genome

54
Q

how many base pairs are on the human genome?

A

about 3 billion

55
Q

what is a mutation?

A

a genetic variation that causes a disease

56
Q

what is a polymorphism?

A

a genetic variation that is prevalent in the population and not, in itself, disease causing

57
Q

what does a promotor mutation result in?

A

no, or reduced transcription/translation

58
Q

result of a base change

A

it alters the amino acid sequence therefore a different or non-functioning protein is produced

59
Q

what is the wild type?

A

the normal DNA sequence

60
Q

name for how to describe a mutation

A

standard nomenclature

61
Q

what does p. mean?

A

the change in the peptide (protein) sequence (letters)

62
Q

what does c. mean?

A

the change in the mature mRNA sequence (amino acid names)

63
Q

standard nomenclature for a stop

A

*

64
Q

c. for deleting a single base and frameshift (the sixth one and its an A)

A

c.6delA

65
Q

what is a trinucleotide repeat expansion?

A

replication of a trinucleotide

66
Q

how many polymorphisms are there?

A

about 3 billion (changes from the ‘normal’

67
Q

any variant in the wild type may be?

A
  • a mutation
  • a variant of uncertain significance
  • a polymorphism
68
Q

what is penetrance?

A

the likelihood of having a disease if you have a gene mutation

69
Q

penetrance in autosomal dominance?

A

100%

70
Q

what generations is an autosomal dominant disease seen in?

A

all generations

71
Q

what causes autosomal recessive diseases?

A

2 faulty copies of gene to cause disease

72
Q

what generations is an autosomal recessive disease seen in?

A

only one generation

73
Q

x linked disease example

A

haemophilia

74
Q

where does the X linked recessive gene lie?

A

gene fault lies on the X chromosome

75
Q

who carries the x linked recessive mutation? will they show features of the disease?

A

Females are carriers and do not show major features of the disease

76
Q

for an affected X-linked female, how will her offspring be affected?

A

half of the male children will be affected and half of the females will be carriers

77
Q

for an affected X-linked male, how will his offspring be affected?

A

all of his male children will be normal and all of female children will be carriers

78
Q

why might a female carrier show mild features of an x-linked disease?

A

x inactivation, half the cells have the working gene on average

79
Q

what does SNP stand for

A

single nucleotide polymorphisms

80
Q

effects of most SNPs

A

no effect

81
Q

what does CNVs stand for?

A

copy number variations

82
Q

what are CNVs?

A

extra or missing stretches of DNA

83
Q

in Mendelian disorders, they have a …….. penetrance and a …… environmental contribution

A

high penetrance and a small environmental contribution

84
Q

in multifactorial disease, a genetic change is …….., penetrance for any one mutation is …..

A

just another risk factor

mutation is low

Principles (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions