Sexual Reproduction in Flowering Plants — BIOLOGY STD 12 Science — Question

State the contribution of Louis Pasteur in understanding the origin of life on earth. Explain the procedure that he followed to arrive at his conclusion.

Match the DDT concentration in Column I with the organisms in an aquatic food chain in Coulmn II.

S. No.	Column I	S. No.	Column II
A.	0.04ppm	i.	Large fish
B.	2.0ppm	ii.	Zooplanktons
C.	0.5ppm	iii.	Fish-eating birds
D.	25ppm	iv.	Small fish

Mrs. Sharma was eager to know the sex of the foetus, which her daughter-in-law was carrying. She was so anxious that she could pay any amount for that. The doctor refused to disclose the result of the test.

1. How can one know the sex of the foetus?
2. Why is disclosing the sex of the foetus banned in our country?
3. What value do you learn from the doctor's act?

Discuss the role of women and communities in protection and conservation of forests.

1. Write the scientific names of the two species of filarial worms causing filariasis.
2. How do they affect the body of infected person(s)?
3. How does the disease spread?

In ecosystem the movement of nutrients is called cycling while the term 'flow' used for energy. Why?

Branching descent and natural selection are the two key concepts of Darwinian Theory of Evolution. Explain each concept with the help of a suitable example.

Two children, A and B aged 4 and 5 years respectively visited a hospital with a similar genetic disorder. The girl A was provided enzyme-replacement therapy and was advised to revisit periodically for further treatment. The girl, B was, however, given a therapy that did not require revisit for further treatment.

1. Name the ailments the two girls were suffering from?
2. Why did the treatment provided to girl A required repeated visits?
3. How was the girl B cured permanently?

A large number of married couples the world over are childless. It is shocking to know that in India the female partner is often blamed for the couple being childless.

1. Why in your opinion the female partner is often blamed for such situations in India? Mention any two values that you as a biology student can promote to check this social evil.
2. State any two reasons responsible for the cause of infertility.
3. Suggest a technique that can help the couple to have a child where the problem is with the male partner.

Write the difference between Darwinism and De Vries theory about evolution of life on earth.