Principles of Inheritance and Variation

Conditions of a karyotype 2n+1 and 2n $\pm\$  2 is called

• Monosomy

• Aneuploidy

• Alloploidy

• Polyploidy

In sickle cell anaemia, glutamic acid is replaced by valine. Which one of the following triplets codes for valine

• GAA

• GAG

• GUA

• GUG

Persons having genotype I^AI^B would show the blood group AB. This is because of

• Pleiotropy

• Co-dominanace

• Segregation

• Incomplete dominanace

The inheritance pattern of a gene over generations among humans is studied by the pedigree analysis. Character studied in pedigree analysis is equivalent to

• Quantative trait

• Mendelian trait

• Maternal trait

• Polygenic trait

Distance between genes and advantages of recombination shows

• direct relationship

• inverse relationship

• parallel relationship

• no relationship

All genes located on the same chromosome

• forms different groups depending upon their relative distance

• form one linkage group

• will not form any linkage groups

• forms interactive group that affect the phenotype

If a haemophilic woman marries a normal man

• all their children will be normal

• all their sons will be haemophilic

• all their daughters will be haemophilic

• 50% sons and 50% daughters will be haemophilic

A woman with normal vision has a colourblind father. she marries a colourblind man. What proportion of their children will be colourblind?

• 25%

• 0%

• 50%

• 100%

In a dihybrid cross if you get 9:3:3:1 ratio, it denotes that

• The alleles of two genes are interacting with each other

• Its multigenic inheritance

• It exhibits multiple allelism

• The alleles of two genes are segregating independently

Ocassionally a single gene may express more than one effect. This phenomenon is called

• multiple allelism

• mosaicism

• pleiotropy

• polygeny