Mineral Nutrition — BIOLOGY STD 11 Science — Question

The skull bones are the strongest bones in the body and thus the brain gets the best protection in the body. In the light of this statement, which of these is true? How will you raise awareness about wearing helmet?

1. We do not need a helmet because skull is enough to take care of the brain.
2. We can manage with a poor quality helmet so that the police does not catch us.
3. Helmets are very important because they help in saving the most important organ; the brain.

What is the difference between cutaneous and pulmonary respiration?

Explain the term “Energy Currency”. Which substance acts as energy currency in plants and animals?

Poison teeth in snakes are called:

1. Incisors
2. Canines
3. Heterodont
4. Fangs

Describe cell division. List various types of cell division. Also mention about the need of cell division?

Colchicine is known to be the mitotic poison. How?

What is fermentation? Name any two organic compounds produced in the process.

Distinguish between:

1. Reducing sugars and non-reducing sugar.
2. Purine and pyrimidine.

Supply a specific scientific term for each of the following:

1. The period between two successive mitotic divisions.
2. Point at which two sister chromatids are held together.
3. Phase in the cell cycle when protein and RNA are synthesised.
4. Nuclear division.

With reasons, explain why a person becomes excessively thirsty if they have a deficiency of vasopressin.