called a factor b) Out of one pair factors one is dominant and the other recessive c) Alleles do not show any blending and both the characters recover as such in F2 generation d) Factors occur in pairs . ABO blood groups in humans are controlled by the gene I. It has three alleles – IA, IB and i. Since there are three different alleles, six different genotypes are possible.
How many phenotypes can occur? [AIPMT PRE ] a) Three b) One c) Four d) Two . Which one of the following symbols and its representation, used in human pedigree analysis is correct? [AIPMT PRE ] a) □ = ○ =Mating between relatives b) ○ =Unaffected male c) □ =Unaffected female d) ◊=Male affected .
Which one of the following conditions correctly describes the manner of determining the sex in the given example? [AIPMT PRE ] a) XO type of sex chromosomes determine male sex in grasshopper b) XO condition in humans as found in Turner syndrome, determines female sex c) Homozygous sex chromosomes(XX) produce male in Drosophila d) Homozygous sex chromosomes(ZZ) determine female sex in birds . A normal-visioned man whose father was blind, marries a woman whose father was also colour blind. They have their first child as a daughter.
What are the chances that this child would be colour blind? [AIPMT PRE ] a) % b) % c) % d) % . Which of the following statements is not true of two genes that show per cent recombination frequency [AIPMT ] a) The genes may be on different chromosomes b) The genes are tightly linked c) The genes show independent assortment d) If the genes are present on the same chromosome . A pleiotropic gene: [RE-AIPMT ] a) Is a gene evolved during Pliocene b) Controls a trait only in combination with another gene c) Controls multiple traits in an individual d) Is expressed only in primitive plants .
A gene showing codominance has: [RE-AIPMT ] a) Alleles tightly linked on the same chromosome b) Alleles that are recessive to each other c)