An example of homologous organs is

Which of the following statement is incorrect?

A zygote which has an X - chromosome inherited from the father will develop into a

New species may be formed if
(i) DNA undergoes significant changes in germ cells
(ii) chromosome number changes in the gamete
(iii) there is no change in the genetic material
(iv) mating does not take place

A basket of vegetables contains carrot, potato, radish and tomato. Which of them represent the correct homologous structures?

The two versions of a trait (character) which are brought in by the male and female gametes are situated on

In peas, a pure tall plant (TT) is crossed with a short plant (tt). The ratio of pure tall plants to short plants in F₂ is

The number of pair (s) of sex chromosomes in the zygote of humans is

The theory of evolution of species by natural selection was given by

Some dinosaurs had feathers although they could not fly but birds have feathers that help them to fly. In the context of evolution this means that

What will be the blood groups of offspring's produced by the parents having following genotype?

What is speciation?

What happened when Mendel crossed two traits of a character in a pea plant?

Why are the small numbers of surviving tigers a cause of worry from the point of view of genetics?

What is the percentage possibility a couple of having daughters?

How is the equal genetic contribution of male and female parents ensured in the progeny?

What is the genotype of tall plants which always produced tall offspring?

If we cross pure-bred tall (dominant) pea plant with pure-bred dwarf (recessive) pea plant we will get pea plants of F₁ generation. if we now self-cross the pea plants of F₂ generation.
(a) What do the plants F₁ generation look like?
(b) State the ratio of tall plants to dwarf plants F₂ generation.
(c) State the type of plants not found in F₁ generation, but appeared in F₂ generation mentioning the reason for the same.

A pea plant with blue colour flower denoted by BB is cross-bred with a pea plant with white flower denoted by ww.
(a) What is the expected colour of the flowers in their F₄ progeny?
(b) What will be the percentage of plants bearing white flower in F₂ generation, when the flowers of F₄ plants were selfed?
(c) State the expected ratio of the genotype BB and Bw in the F₂ progeny.

State the importance of chromosomal difference between sperms and eggs of humans.

Explain with examples, how the following are evidences in favour of evolution in organisms.
(i) Homologous organs
(ii) Analogous organs
(iii) Fossils.

List three distinguishing features in tabular form between acquired trait and inherited trait.

(a) Name any four varieties of vegetables which have been produced from 'wild cabbage' by the process of artificial selection.
(b) Give one example of an evolutionary change produced in an organism for one purpose which later on becomes more useful for a different function.

A blue colour flower plant denoted by BB is crossbred with that of white colour flower plant denoted by bb.
(a) State the colour of flower you would expect in their F₁ generation plants.
(b) What must be the percentage of white flower plants in F₂ generation if flowers of F₁ plants are self-pollinated?
(c) State the expected ratio of the genotype BB and Bb in the F₂ progeny.

Explain the various stages of evolution.

(a) Why did Mendel choose garden pea for his experiment? Write two reasons.
(b) List two contrasting visible characters of garden pea Mendel used for his experiment.
(c) Explain in brief how Mendel interpreted his results to show that the traits may be dominant or recessive.

What is meant by speciation? List four factors which could lead to speciation. Which of these cannot be a major factor in the speciation of a self-pollinating plant species. Give reason to justify your answer.