Brainscape's Knowledge GenomeTM

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


See full index

Revision (OT) > Genetics Revision Lecture > Flashcards

Genetics Revision Lecture Flashcards

1
Q

What is the central dogma?

A

DNA to RNA through Transcription + Splicing

RNA to protein through translation

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

What structural element of DNA prevents transcription?

A

It’s association with histone proteins

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

What are the main differences between RNA & DNA?

A

RNA is single stranded. Ribose is present rather than deoxyribose in its nucleotides. Finally, it has Uracil instead of adenine

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

What is splicing?

A

The removal of introns from pre mRNA to form mRNA.

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

What are the stages of the cell cycle?

A 
G0 - cell doing celly things 
G1 - growth
S- DNA synthesis 
G2- growth & prep for mitosis 
M- mitosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the function of DNA helicase?

A

DNA helicase breaks the hydrogen bonds between the DNA strands, it “unzips the DNA”

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

What is the role of DNA polymerase in DNA synthesis.

A

DNA polymerase copies the DNA strands.

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

What are Okazaki fragments?

A

These are small fragments of connected nucleotides created by DNA polymerase from the 3’-5’ DNA strand.

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

What is the function of DNA ligase?

A

To join the Okazaki fragments into a full DNA strand.

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

What are the differences between Mitosis and Meiosis?

A

Mitosis - 2 genetically identical diploid daughter cells.

Meiosis- 4 genetically variable haploid cells.

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

What is a polymorphism?

A

A DNA variant that has a population frequency of greater than 1%.
Doesn’t have to cause disease.

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

What is a mutation?

A

DNA variant which causes or predisposes to a specific disease

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

What is a premature stop mutation?

A

The codon sequence ends early due to a new stop codon

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

What is a missense mutation?

A

A base changes so the codon is sequence is now incorrect

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

What is an insertion mutation?

A

Base inserted in the sequence

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

What is ab Out of frame deletion mutation?

A

Base or 2 deleted so all the triplets in the sequence change

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

What is an In frame deletion mutation?

A

Multiple of 3 bases or triplet or 2 are deleted so remaining triplets don’t change.

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

What is a triplet expansion mutation?

A

A triplet of bases are duplicated

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

What is the base excision pathway of DNA repair?

A

Damaged bases are removed

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

What is the nucleotide excision pathway of DNA repair?

A

Dimerised bases are removed (thymine bases, occurs due to UV light)

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

What is the mismatch pathway of DNA repair?

A

Mismatched bases are removed.

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

What is homologous recombination? (DNA repair pathway)

A

A DNA sequence from the sister chromatid is used to fill a double strand break

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

What is non-homologous end joining? (DNA repair pathway)

A

The 2 ends of a double strand break are joined together (lots of mistakes happen here)

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

What are the advantages of karyotyping?

A

Karyotyping allows you to identify large deletiosn (>5mbp), can see location of centromeres, acrocentric chromosomes, aneuploidy, sex chromosomes & translocations

25
Q

What is a balanced translocation?

A

An even exchange of genetic material between chromosomes, no missing or extra material. Normally fully functioning.

26
Q

What is an unbalanced translocation?

A

Exchange of genetic material is unequal resulting in extra or missing information

27
Q

What is an Acrocentric chromosome?

A

A chromosome where the centromere is located very near the end of the chromosome

28
Q

Why can an Acrocentric chromosome predispose to cancer?

A

2 acrocentric chromosomes can stick together, these are common in cancer.

29
Q

What does FISH involve?

A

FISH involves using a flouresent probe to attach to a gene

30
Q

What is FISH good for identifying?

A

It is good for identifying specific changes such aneuploidy or translocations with a gene. (Need to know what you’re targeting)

31
Q

What is ACGH?

A

Array comparative genomic hybridisation. Fluorescent markers with wells of patient & control DNA. Differences in colour mean changes in gene expression.

32
Q

What does Next generation sequencing allow for?

A

It allow for massive, parallel sequencing of genomes or exomes (exons only).

33
Q

What is the problem with Next generation sequencing?

A

You gain a huge number of results that you have to filter through. Unknown if mutations, polymorphous, variants of uncertain significance

34
Q

Autosomal dominant pattern of inheritance?

A

Affected individuals in every generation. M + F affected. All forms of transmission are present.

35
Q

Autosomal recessive pattern of inheritance?

A

Affected individuals are usually in one sibship in one generation. M+F affected. Disease often skips generations. Increases risk with consanguinity.

36
Q

X-linked recessive pattern of inheritance?

A

Males affected almost exclusively. Transmitted from female carriers to sons. Affected males cannot transmit the condition to their sons.

37
Q

Risk of autosomal dominant pattern of inheritance?

A

If there is an affected mother, risk of an affected child is 50%

38
Q

Risk of autosomal recessive pattern of inheritance?

A

Normal Risk of affected child 25%

39
Q

Risk of X-linked recessive pattern of inheritance?

A

Risk of affected child 25% Risk of carrier child 25%

40
Q

What is Expression?

A

The process by which information from a gene is used in the synthesis of a functional gene product.

41
Q

What is Penetrance?

A

The extent to which a particular gene is expressed in the phenotype of an individual carrying it.

42
Q

What is X-inactivation?

A

A cell only requires one working copy of the X chromosome. In females, each cell has a random X chromosome inactivated.

43
Q

What is meant by Multi-Factorial disease?

A

Mutations in multiple genes combined with environmental factors to cause disease. These genes display low penetrance.

44
Q

Common disease- common variant hypothesis

A

States mendelian diseases are due to rare variants which have a huge effect on the body. Common diseases are due to common variants (and environment factors) which each have a small effect on the body.

45
Q

How does DNA methylation and acetylation impact transcription?

A

These both impact how tightly DNA is wrapped around its associated histone proteins. This means they impact the rate of transcription.

46
Q

What is Imprinting?

A

Maternal or paternal inheritance will cause differences in gene expression

47
Q

What is Mitochondrial DNA inheritance?

A

Almost exclusively maternal inheritance of genes for mitochondrial metabolic pathways and ribosomal RNAs.

48
Q

What are oncogenes?

A

These genes when activated are associated with cancer.

49
Q

What are tumoursupressor genes?

A

These genes regulate expression, inactivation is associated with cancer.

50
Q

What is the 2 hit hypothesis?

A

2 hits are needed to inactivate a gene due to the 2 alleles. These can be inherited or an acquires, somatic mutation.

51
Q

What is mosaicism?

A

Present of 2 or more population of genotypical different cells in one individual.

52
Q

What is somatic mosacisim?

A

Post-zygotic mutation derived. Not inherited.

53
Q

What is gonadal mosacisim?

A

2 populations of cells in the gonads. Will be inherited.

54
Q

6 hallmarks of cancer?

A 
Sustaining proliferative signalling 
Evading growth suppressors 
Resisting cells each 
Inducing angiogenesis 
Enabling replicative immortality 
Activating invasion and metastasis
55
Q

What is the CTFR protein?

A

This is a channel protein that regulates chloride ions and thus movement of water ions.

56
Q

What is the population carrier frequency of CF?

A

1 in 24/25

57
Q

2 most common CF mutations?

A

F508del

G551D

58
Q

How do you calculate risk of inheritance?

A

Maternal risk x Paternal risk x chance of passing on 2 copies of genes = risk

Revision (OT) (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions