A baby has been born with a small tail. It is a case exhibiting

• retrogressive evolution

• mutation

• atavism

• metamorphosis

Given below is a pedigree chart of a family with five children. It shows the inheritance of attached ear-lobes as opposed to the free ones. The squares represent the male individuals and circles the female individuals. Which one of the following conclusions drawn is correct

• The parents are homozygous recessive.

• The trait is Y-linked.

• The parents are homozygous dominant.

• The parents are heterozygous.

Given below is a representation of a kind of chromosomal mutation. What is the kind of mutation represented

• Deletion

• Duplication

• Inversion

• Reciprocal translocation

How many different types of gametes can be formed by F₁ progeny, resulting from the following cross

AA BB CC x aa bb cc

• 3

• 8

• 27

• 64

Assertion : In humans, the gamete contributed by the male determines whether the child produced will be male or female.

Reason : Sex in humans is a polygenic trait depending upon a cumulative effect of some genes on X chromosome and some on Y-chromosome.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false

• If both Assertion and Reason are false

One of the genes present exclusively on the X-chromosome in humans is concerned with

• baldness

• red-green colour blindness

• facial hair/moustaches in males

• night blindness

Mirabilis jalapa is an example of

• complete dominance

• supplementary gene

• incomplete dominance

• complementary gene

Which of the following is dominant character according to Mendel ?

• Dwarf plant and yellow fruit

• Terminal fruit and wrinkled seed

• White testa and yellow pericarp

• Green coloured fruit and rounded seed

Lack of independent assortment of genes A and B in fruit fly Drosophila is due to :

• repulsion

• linkage

• crossing-over

• recombination

When two mutations are located in the same functional unit or in different functional units, then it is confirmed by :

• test cross

• back cross

• reciprocal cross

• complementation test