Human Reproduction — BIOLOGY STD 12 Science — Question

A normal visioned woman, whose father is colour blind, marries a normal visioned man. What would be the probability of her (a) sons (b) daughters to be colour blind? Explain with the help of pedigree chart.

Describe various methods of contraception for the population control.###What are the main types of methods of birth control?###Discuss use of Various Contraceptive measures used for population.

A pregnant human female was advised to undergo M.T.P. It was diagnosed by her doctor that the foetus she is carrying has developed from a zygote formed by an XX egg fertilised by Y–carrying sperms. Why was she advised to undergo M.T.P.?

Write the symptoms of haemophilia and sickle-cell anaemia in humans. Explain how the inheritance pattern of the two diseases differ from each other.

What is ecological pyramid? Write its types and give a diagrammatic representation of the pyramid of biomass in the ocean.

What develops into a microspore mother cell in a flower? Trace the development of this cell into a pollen grain which is ready for germination. Draw a labelled figure of a mature pollen grain.

Diseases like dysentery, cholera, typhoid etc., are more common in over crowded human settlements. Why?

What are hallucinogens? Give two examples. Mention their clinical use, if
any.

Vivipary automatically limits the number of offsprings in a litter. How?

What is meant by immunity? What are the four barriers to innate immunity? Explain . Draw a labelled diagram of the structure of an antibody molecule.