Genetic variation introduction

Question 1

What is found at the end of each arm of a chromosome?

Answer 1

Telomere

Question 2

What letter is given to the short arm of a chromosome?

Answer 2

P

Question 3

What letter is given to the long arm of a chromosome?

Answer 3

Q

Question 4

What is an acrocentric chromosome?

Answer 4

A chromosome that only has a long arm

Question 5

What is a balanced chromosome rearrangement?

Answer 5

A rearrangement in which all chromosomal material is present

Question 6

What is an unbalanced chromosome rearrangement?

Answer 6

A rearrangement in which there is missing or extra chromosomal material

Question 7

What is a aneuploidy?

Answer 7

A condition in which there is a whole extra or missing chromosome

Question 8

What is a translocation?

Answer 8

The rearrangement of chromosome

Question 9

What is a microdeletion?

Answer 9

A deletion that is too small to see when karyotyping

Question 10

What is the medical name for Down’s syndrome?

Answer 10

Trisomy 21

Question 11

What is the cause of Trisomy 21?

Answer 11

An extra chromosome 21

Question 12

What is the karyotype of a male with Down’s syndrome?

Answer 12

47XY + 21

Question 13

What is the medical name for Edward’s syndrome?

Answer 13

Trisomy 18

Question 14

What is the cause of Trisomy 18?

Answer 14

An extra chromosome 18

Question 15

What is the karyotype of a male with Edward’s syndrome?

Answer 15

47XY + 18

Question 16

What is a Robertsonian translocation?

Answer 16

A translocation in which 2 acrocentric chromosomes attach end to end

Question 17

What is the cause of Turner syndrome (Monosomy X)?

Answer 17

A missing X chromosome in a female

Question 18

What is the karyotype of a female with Turner syndrome?

Answer 18

45X

Question 19

What is the karyotype of a female with triple X syndrome?

Answer 19

47XXX

Question 20

What is the cause of Triple X syndrome?

Answer 20

An extra X chromosome in a female

Question 21

What is the cause of Klinefelter syndrome?

Answer 21

An extra X chromosome in a male

Question 22

What is the karyotype of a male with Klinefelter?

Answer 22

47XXY

Question 23

What is a reciprocal translocation?

Answer 23

A translocation in which a section of one chromosome is swapped with a section of another chromosome

Question 24

What is array CGH?

Answer 24

A genome wide genetic test that shows the number of a each gene, allowing deletions and insertions to be shown

Question 25

What is mosaicism?

Answer 25

Different cells have a different genetic constitution

Question 26

What does Next generation sequencing allow?

Answer 26

Large scale sequencing

Question 27

What is a mutation/ pathogenic variation?

Answer 27

A genetic variation that causes a disease

Question 28

What is a polymorphism/ benign variant?

Answer 28

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

Question 29

What is the most common base mutation?

Answer 29

From cytosine to thymine

Question 30

What is a premature stop mutation?

Answer 30

A mutation in which a codon mutates to form a stop codon earlier in the sequence

Question 31

What is a missense mutation?

Answer 31

A mutation in which one base is mutated into another

Question 32

What is an insertion mutation?

Answer 32

A mutation in which an extra base is added to the sequence, resulting in a frame shift

Question 33

What is a deletion mutation?

Answer 33

A mutation in which a base is removed from the sequence, resulting in a frame shift

Question 34

What is a triplet expansion mutation?

Answer 34

A mutation in which a DNA triplet is replicated

Question 35

How is a change in base sequence displayed?

Answer 35

c. (base number) (initial base)>(mutated base)

Question 36

How is a change in protein sequence displayed?

Answer 36

p. (initial amino acid) (amino acid number) (Mutated amino acid)

Question 37

How is a stop codon displayed in nomenclature?

Answer 37

Ter or *

Question 38

How is a deletion displayed?

Answer 38

c. (base number) del (base)

Question 39

How is a frame shift represented in nomenclature?

Answer 39

fs

Question 40

What is the effect of a change in promotor or splice sequence?

Answer 40

Can stop transcription or cause abnormal splicing

Question 41

What are the steps of filtering?

Answer 41

Exclude if it is a known polymorphism Keep if affects gene function (stop, splice) Is it in a gene that affects phenotype

Question 42

What is penetrance?

Answer 42

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

Question 43

What type of inheritance causes blood related disorders and blood types?

Answer 43

Co-dominant inheritance (2 dominant genes)