Genetics and evolution

Question 1 of 10

In a dihybrid cross of two heterozygotes (AaBb × AaBb), the expected phenotypic ratio is

Question 2 of 10

A person with blood group AB has the genotype

Question 3 of 10

A cross between a homozygous tall plant (TT) and a homozygous short plant (tt) gives offspring that are

Question 4 of 10

In a cross Rr × rr, the probability that an offspring is homozygous recessive is

Question 5 of 10

A trait controlled by many genes, such as skin colour, shows

Question 6 of 10

Allopatric speciation occurs when populations are

Question 7 of 10

Down syndrome is caused by an extra copy of chromosome

Question 8 of 10

Sickle-cell anaemia is an example of

Question 9 of 10

A cross between two heterozygous tall plants (Tt × Tt) gives a phenotypic ratio of

Question 10 of 10

In a population where the recessive allele frequency q = 0.4, the frequency of heterozygotes (Aa) is