Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

What do you understand by co-dominance? Explain the co-dominance by taking example of blood group in human.

Define transformation in Griffith's experiment. Discuss how it helps in the identification of DNA as the genetic material.

Embryo sacs of some apomictic species appear normal but contain diploid cells. Suggest a suitable explanation for the condition.

A dihybrid heterozygous round, yellow seeded garden pea was crossed with a double recessive plant.

1. What type of cross is this?
2. Work out the genotype and phenotype of the progeny.
3. What principle of Mendel is illustrated through the result of this cross?

In a sea shore, the benthic animals live in sandy, muddy and rocky substrata and accordingly developed the following adaptations.

1. Burrowing.
2. Building cubes.
3. Holdfasts/ peduncle.

Find the suitable substratum against each adaptation.

To maintain the continuity of its life, Plasmodium protozoa requires both mosquito and human hosts.” Explain.

Soil pollution is mainly caused by agrochemicals. Justify.

Write differences between self-pollination and cross-pollination.

1. Sickle celled anaemia in humans is a result of point mutation. Explain.
2. Write the genotypes of both the parents who have produced a sickle celled anaemic offspring.

Somatic chromosome number is 40. What shall be the chromosome number in the cells of seminiferous tubules?