Evolution — BIOLOGY STD 12 Science — Question

Select the analogous structures from the combinations given below:

1. Forelimbs of whales and bats
2. Eyes of octopus and mammals
3. Tuber of sweet potato and potato
4. Thorns of Bougainvillea and tendrils of Cucurbita

2. ​​​​​​​State the kind of evolution they represent.

When the relative frequency of the different phenotypes of a cross is plotted graphically, a bell-shaped curve results. Mention any four characteristics of such a pattern of inheritance.

Name the host and the site where the following occur in the life-cycle of a malarial parasite:

1. Formation of gametocytes.
2. Fusion of gametocytes.

Who proposed the chromosomal theory of inheritance? Point out any two similarities in the behaviour of chromosomes and genes.

Why is ZIFT a boon to childless couples? Explain the procedure.

How are the DNA fragments separated by gel electrophoresis visualised and separated for use in constructing recombinant DNA.

With the help of an algebraic equation, how did Hardy-Weinberg explain that in a given population the frequency of occurrence of alleles of a gene is supposed to remain the same through generations?

Categorise the following pairs of examples as convergent or divergent evolutions:

1. Eyes of Octopus and mammals.
2. Wings of butterfly and birds.
3. Tuber of sweet potatoes and potato.
4. Thorns in Bougainvillea and tendrils in Cucurbits.

How has mutation breeding helped in improving the production of mung bean crop?

Name two fruits each with:

1. Fleshy pericarp and
2. Dry pericarp.