3.4 Inheritance

Question 1

Genotype vs Phenotype

Answer 1

Phenotype: Trait expressed
Genotype: genes expressed

Question 2

Codominance

Answer 2

both allele equally expressed (heterozygous)

Question 3

Autosomal recessive disease

Answer 3

Cystic fibrosis - clogged airway due to excess production of sticky and thick mucus leading to respiratory problems

Question 4

Autosomal dominant disease

Answer 4

Huntington’s disease - mutation of HTT gene leading to misfolding of protein structure leading to neurodegeneration in middle ages

Question 5

Codominant disease

Answer 5

Sickle cell anaemia leads to sickle-shaped blood cells that damage blood vessels (if only one copy milder symptoms)

Question 6

Mutagens and carcinogens

Answer 6

mutagens: agents that increase the rate of mutation
carcinogens: ones that lead to cancer

Question 7

Incompatible blood

Answer 7

Haemolysis - rupturing of red blood cells

Question 8

Sex-linked inheritance examples

Answer 8

Haemophilia X^H X^h - impaired ability for blood clotting (recessive)
Red green colour blind X^A X^a - inability to distinguish red and green due to mutation in red or green retinal receptor (recessive)

Question 9

Mendelian ratio

Answer 9

3:1

Question 10

Effect of Hiroshima and Chernobyl

Answer 10

Death, thyroid cancer, impaired immune function