Brainscape's Knowledge GenomeTM

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


See full index

Year 1- Principles of Disease (FOM) > Mutations and Genetic Analysis > Flashcards

Mutations and Genetic Analysis Flashcards

1
Q

Name the three subtopics of chromosomal abnormalities.

A

Numerical
Structural
Mutational

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

Describe numerical chromosomal abnormalities.

A

The wrong number of chromosomes is present in a karyotype, not the normal number of 46.

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

Describe structural chromosomal abnormalities.

A

A large-scale rearrangement where chromosomes have fused, or gross change has taken place.

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

Describe mutational chromosomal abnormalities.

A

Smaller scale changes which are revealed through more detailed molecular approaches.

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

Define trisomy.

A

An extra copy of a chromosome is present in the cell nuclei, causing developmental abnormalities.

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

Why do numerical chromosome abnormalities occur?

A

Due to a failure of disjunction during meiosis.

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

What can happen in disfunction during meiosis?

A

Both of the homologs may end up in the same cell.

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

What happens if the sister chromatids fail to sperate at the second mitotic division?

A

Can result in diisomy where two sister chromatids end up in one of the gametes,

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

What is trisomy 21 better known as?

A

Down’s Sydrome

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

What increases the risk of Down’s sydrome?

A

An increase in maternal age.

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

Discuss some characterisations that individuals with Down’s syndrome may have.

A

-Characteristic facial dysmorphologies
-IQ less than 50
-Average life expectancy (50-60 years)
-Alzheimer’s disease in later life

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

What is the other name for trisomy 13?

A

Patau syndrome`

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

Name two features of Patau Syndrome

A

-Multiple dysmorphic features and mental retardation
-About 5% die within first month, very few survive beyond first year

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

What is the other name for trisomy 18?

A

Edwards syndrome

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

Describe the survival rates for those with Edward’s Syndrome.

A

Severe developmental problems; most patients die within first year, many within first month

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

When do sex chromosome aneuploidy syndromes occur?

A

When there’s an abnormal number of sex chromosomes.

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

What syndrome has 45 chromosomes and one X gamete?

A

Turner’s syndrome

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

Describe some features of those with Turner’s syndrome.

A

Females of short stature and infertile
Neck webbing and widely spaced nipples
Intelligence and lifespan is normal

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

Will individuals with Turner’s Syndrome be male, female or both?

A

Female as only one X chromosome

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

Which syndrome occurs in individuals with 47 chromosomes and the gametes XXY?

A

Klinefelter syndrome

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

Describe some features of those w Klinefelter syndrome

A

Tall stature, long limbs
Male but infertile, small testes, about 50% gynaecomastia
Mild learning difficulties

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

What can a structural abnormality involve?

A

-Balanced or unbalanced rearrangements
-Translocation mutation
-Deletion mutation
-Insertion mutation
-Inversion mutation

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

Name the two types of translocation.

A

Reciprocal
Robertsonian

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

Describe Robertsonian translocation

A

Fusion of two acrocentric chromosomes

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

Describe Reciprocal translocation.

A

Involving breaks in two chromosomes with formation of two new derivative chromosomes

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

What does balanced translocation look like?

A

Two completely different chromosomes which exchange large sections of information

-Same number of copies of all the original DNA are still presen

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

What will happen if a gamete inherits two normal chromosomes?

A

Gamete may inherit two normal chromosomes. If fertilised by a normal gamete, everything should be fine.

28
Q

What will happen if a gamete inherits one chromosome w a balanced translocation?

A

Iif fertilised by a normal zygote, will probably result in a normal phenotype too despite the translocation.

29
Q

What will happen if a gamete inherits one normal chromosome and another with an unbalanced chromosome?

A

The gametes will be unbalanced and do not have the normal complement of DNA. If fertilised by a normal gamete, there will still be an abnormal amount of DNA.

30
Q

What happens in the Robertsonion translocation?

A

The information which is usually present on two different chromosomes is now on one.

31
Q

What would happen if we have a Robertsonian translocation that involves chromosome 21 and 14?

A

Gamete formed in unbalanced.

If fertilized by a normal gamete, it may lead to trisomy 21 or trisomy 14.

32
Q

How can large-scale deletions be caused?

A

Breaks forming in chromosomes.

If normal repair fails to happen, DNA material instead gets deleted resulting in a chromosome which has lost material.

33
Q

How can inversions occur?

A

When a large piece of DNA is reversed.

-Usually balanced so doesn’t normally have a phenotypic effect.

34
Q

Where can genetic mutations arise?

A

In the germ line or somatic cells.

35
Q

What can gene mutations do?

A

Disrupt genes and bring about gene associated disease

36
Q

What are polymorphism mutations?

A

Don’t have any phenotypic effect and no apparent differences but there are slight differences.

37
Q

Name the two broad subtopics of mutation which might arise.

A

Coded
Non-coded

38
Q

Describe non-coding DNA mutations.

A

Mutations and changes that take place in DNA that doesn’t directly code for protein but could have an effect if in a promoter region that’s involved in controlling the transcription of a gene.

39
Q

What kind of coding mutations may there be?

A

Silent
Missense
Nonsense
Frameshift

40
Q

Give an example of a silent mutation.

A

Synonymous (doesn’t change the amino acid coded for)

e.g. CGA (Arg) to CGC (Arg)
->has no effect as both sequences code for argenine

41
Q

Give an example of a missense mutation.

A

CGA (Arg) to GGA (Gly)

->change from arginine to glycine which may have a major impact on the function of the protein.

42
Q

Give an example of a nonsense mutation.

A

CGA (Arg) to TGA (Stop)

->TGA is a stop codon

43
Q

Give an example of a frameshift mutation.

A

Insertion or deletion

44
Q

Name some processes that can be used to detect mutations.

A

-Polymerase chain reaction (PCR)
-Gel electrophoresis
-Restriction fragment length polymorphism (RFLP) analysis
-Amplification refractory mutation system (ARMS)
-DNA sequencing

45
Q

Is PCR in vivo or in vitro?

A

In vitro

46
Q

What is required to do a PCR?

A

-Sequence information
-Oligonucleotide primers
-DNA
-Nucleotides
-DNA polymerase

47
Q

What is the aim of PCR?

A

To amplify a region of DNA

48
Q

Describe the steps of the Polymerase Chain Reaction.

A

Step 1- denature at 93-95 degrees
Step 2- anneal at 50-70 degrees
Step 3- Extend ay 70-75 degrees

Repeat process 20-30 times

49
Q

Define the process of annealing relating to DNA

A

When the temperature is lowered to enable the DNA primers to attach to the template DNA.

50
Q

What is used to extend the DNA during PCR?

A

Thermo resistant DNA polymerase

51
Q

What process would you do after PCR?

A

Gel electrophoresis

52
Q

Explain the purpose of gel electrophoresis

A

Separates DNA fragments by size.

53
Q

Describe gel electrophoresis takes place.

A

Apply an electric field
DNA is negatively charged so will separate through agarose gel matrix and allows us to visualise DNA fragments

54
Q

List some advantages of PCR

A

-Quick
-Easy to use
-Sensitive
-Robust

55
Q

Name some applications of PCR.

A

-DNA cloning
-DNA sequencing
-In vitro mutagenesis
-Gene identification
-Gene expression studies
-Forensic medicine
-Typing genetic markers
-Detection of mutations

56
Q

What is ARMS?

A

Amplification Refractory Mutation System

->a simple method for detecting any mutation involving single base changes or small deletions.

57
Q

List some advantages of ARMS

A

-Cheap
-Labelling not required
-Electrophoresis required
-Primer design critical

58
Q

List some disadvantages of ARMS

A

-Need sequence information
-Limited amplification size

59
Q

What are restriction endonucleases?

A

Enzymes originally derived from bacterial cells which are biologically a protective mechanism to degrade the DNA of invading viruses.

60
Q

Does the site in which restrictive endonuclease cut the DNA differ?

A

No, always cuts DNA at the same site.

61
Q

What is RFLP analysis used for?

A

Finds where a specific gene for a disease lies on a chromosome

62
Q

Name some advantages of RFLP analysis.

A

Simple
Cheap
Non-radioactive

63
Q

List some disadvantages of RFLP analysis.

A

Requires gel electrophoresis
Not always feasible

64
Q

What method does most DNA sequencing involve?

A

Involves the chain termination method

65
Q

List some advantages of DNA sequencing.

A

-Gold standard for mutation detection
-Automation and high throughput

66
Q

List some limitations of DNA sequencing

A

Expensive equipment
Poor quality sequence read

Year 1- Principles of Disease (FOM) (40 decks)

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