Biology Past Questions and Answers

People wit sickle-cell anaemia have haemoglobin

A S and are homozygous recessive
B A and are heterozygous recessive
C S and are heterozygous recessive
D A and are homozygous recessive

Question 42:

In the gene locus for eye colour in humans, the allele for brown eye is dominant over the allele for blue eyes. If a homozygous brown-eyed girl has a brother with blue eyes, what are the likely phenotypes of there parents'eye colour (Eye colour is not a sex linked trait)

A Both parents have blue eyes
B Their father has blue eyes and their mother has brown eyes
C Both parents have brown eyes
D Their mother has the blue eyes and their father has the brown eyes

Question 43:

If a woman's genotype is Tt Qq Rr, what would be the gene content of her eggs?

A TQr, tqr
B TQR, tqr
C TqR, tQr
D TQr, TQR

Question 44:

The sex-linked defect in which very slight cut produces severe bleeding is known as

A Anaesmia
B Anorexia
C Haemophilia
D Haemolysis

Question 45:

A man who has the trait for colour blindness marries a normal woman. What percentage of their children would be sufferers, carriers and normal respectively

A 25%, 25% and 50%
B 25%, 50% and 25%
C 50%, 25% and 25%
D 25%, 37.5% and 37%