Respiration and Circulation — BIOLOGY STD 12 Science — Question

Eurythermal and stenothermal.

Food chains do not exist in isolation, but are always interconnected to form food web.

List three strategies that a bisexual chasmogamous flower can evolve to prevent self pollination (autogamy).

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.

Draw the neat labelled diagrams.
a. Human ear.
b. Sectional view of human eye.
c. Draw the neat labelled diagram of sagittal section or L.S. of human brain
d. Draw the neat labelled diagram of Multipolar Neuron.

Cranial nerves and Spinal nerves

Complete the given table.

Name of the organism	Product/ Enzyme/ Bioactive male cule
Aspergillus niger	(i)
(ii)	Ethanol
(iii)	Cyclosporin-A
(iv)	Acetic acid
Monascus purpureus	(v)
Streptococcus	(vi)

Endosperm.

Trace the origin and evolution of Man.

Differentiate between dominance and co–dominance.