Genetics

Question 1

Name the order of the cell cycle?

Answer 1

G1 -> S -> G2 -> M -> G1

Question 2

When does DNA synthesis occur?

Answer 2

S phase

Question 3

What happens in mitosis?

Answer 3

One diploid parent cell becomes 2 identical diploid daughter cells

Question 4

What happens in meiosis?

Answer 4

One diploid parent cell becomes 4 haploid daughter cells
Crossing over occurs
Gamete formation

Question 5

What is a polymorphism?

Answer 5

Any variation in human genome which has a population frequency >1%

• Does not cause disease in own right
• May predispose to common disease

Question 6

What is a multifactorial disease?

Answer 6

Multiple polymorphisms cause a risk of disease

Question 7

What is a classic genetic dieases?

Answer 7

One mutation sufficient to cause disease

Question 8

What chromosome arrangement does a normal female have?

Answer 8

46 XX

Question 9

What is aneuploidy?

Answer 9

Whole extra or missing chromosome

Question 10

What is Robertsonian Translocation?

Answer 10

Two acrocentric chromosomes stuck end to end

Increases risk of trisomy in pregnancy

Question 11

What is 47 XY + 21?

Answer 11

Down syndrome, trisomy 21

Question 12

What is 47 XY + 14?

Answer 12

Miscarriage, trisomy 14

Question 13

What is 47 XY +18?

Answer 13

Edward Syndrome, trisomy 18

Question 14

What is 45 X?

Answer 14

Turner syndrome

Question 15

What is 47 XXY?

Answer 15

Klinefelter syndrome

Question 16

What is a medelain disorder?

Answer 16

a disease that is caused by a change in a single gene

Question 17

What are X linked mutations?

Answer 17

• Recessive
• Y chromosome almost irrelevant
• Haemophilia
• If mother carrier, 50% chance daughter carrier, 50% chance male affected
• No male-male transmission

Question 18

How is mitochondrial DNA usually inherited?

Answer 18

maternal

Question 19

What is imprinting?

Answer 19

• Differences in gene expression depending on whether a gene is maternally or paternally inherited
• Specific chromosomal regions contain imprinted genes
• Such regions usually contain both maternally and paternally imprinted genes

Question 20

What is Angleman Syndrome?

Answer 20

Neuro-genetic disorder - developmental and learning disabilities, frequent laughing and smiling
Chromosome 15

Question 21

What is FISH?

Answer 21

Fluorescence in situ Hybridisation

Can light up specific bit of chromosome if you know which bit to light up

Question 22

What genes ususally code for breast cancer?

Answer 22

BRCA1 and BRCA2 genes