(a) Work out a cross upto F2-generation between true breeding tall pea plants bearing violet flowers and dwarf pea plants bearing white flowers.

(b) Explain Mendel’s laws of segregation and independent assortment on the basis of the cross.

OR

Answer the following questions based on the experiment conducted by S.L. Miller in 1953:

(a) Name the gases present in the closed flask.

(b) Why was the flask fitted with electrodes?

(c) Write the observation he made.

(d) State the significance of the observation made by him.

a)

b) When the parent contains 2 alleles during gamete formation and the factor segregate from each other and do not blend such that a gamete receives only one of the two factors is known as the law of segregation. It is a universally accepted law.

When two pairs of traits are combined in a hybrid then segregation of one pair of characters is independent of the other pair of characters. This is the law of Independent Assortment.

OR

a) The gases present in the closed flask were: Methane, carbon dioxide, ammonia and hydrogen.

b) The flask was fitted with electrodes so as to generate electric charge to provide high temperature upto 800 degrees Celsius.

c) The significance of the observation made was that it helped us formulate the hypothesis that life could have evolved from non-living organic molecules which would have been giant molecules. This is what we know as the theory of biogenesis.