Genetics

Question 1

Define autosomal dominant diseases

Answer 1

Only one dominant allele is needed for diease to be prevalent (failial hypercholesterolaemia)

Question 2

Define autosomal recessive diseases

Answer 2

Both parents must be carriers and both alleles must be recessive (cystic fibosis)

Question 3

Sex-linked inheritance options

Answer 3

Y-linked, X-linked recessive, X-linked dominant

Question 4

Mitochondrial DNA is inherited from which parent

Answer 4

Mother

Question 5

Y-linked diseases

Answer 5

Webbed feet, Hypertrychosis (hairy ears)

Question 6

X-linked recessive diseases

Answer 6

Red-green colour blindness, Haemophilia (defective factor 8 in blood clotting)

Question 7

X-linked dominant diseases

Answer 7

Vitamin D-reistant rickets

Question 8

Define Consanguinity

Answer 8

Mating of individuals closer than 2nd cousins

Question 9

Inbreeding genetic defects

Answer 9

Ataxia (walking/balance), Telangiectases (clusters of enlarged blood vessels close to the eye), High levels of a-fetoprotein in blood

Question 10

What are the 2 main methods of mutagenesis generation?

Answer 10

Radiation and Chemical

Question 11

Examples of chemical mutagen agents

Answer 11

Intercalating agents, Alkylating agents, Oxidising agents

Question 12

Examples of radiation mutagen agents

Answer 12

X-ray, gamma-ray, a particles, b particles, neutrons, K40, Ra222, UV

Question 13

What are silent, substitution, insertion and deletions?

Answer 13

Silent = no change in primary amino acid structure despite mutation
Substitution = Change in amino acid due to a swap in bases
Insertion = addition of bases
Deletion = deletion of bases

Question 14

List the types of chromosomal abnormality

Answer 14

Deletion = Missing section
Translocation = Exchange of segments
Inversion = End-to-end switchover of a section
Duplication = duplication of certain parts