Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Correct the following statements:

1. Surgical methods of contraception prevent gamete formation.
2. All sexually transmitted diseases are completely curable.
3. Oral pills are very popular contraceptives among the rural women.
4. In E. T. techniques, embryos are always transferred into the uterus.

Write the location and function of the Sertoli cells in humans.

Which part in the male reproductive system stores sperms?

Name the special type of tissue enabling plants like lotus and water hyacinth to survive in aquatic environment. Mention any two specific functions of this tissue?

Discuss briefly about seed viability.

Mention the three connotations of the theory of special creation.

Study the given flow chart and answer:

1. Name the defence mechanism used.
2. In which plant it has been done?
3. Name the pathogen.
4. Name the vector used in this technique.

Study the given pedigree chart and answer the questions that follow:

Give the genotypes of the parents in generation I and of their third and fourth child in generation II.

Answer the following questions:
Would Western Ghats ecosystems be less functional if one of its tree frog species is lost forever? Substantiate your answer in the light of hypothesis proposed by Paul Ehrlich.

Study the graph given below and answer the question that follow:

1. Write the status of food and space in the curves (a) and (b).
2. In the absence of predators, which one of the two curves would appropriately depict the prey population?
3. Time has been shown on X-axis and there is a parallel dotted line above it. Give the significance of this dotted line.