Neural Control and Coordination — BIOLOGY STD 11 Science — Question

Given below are types of cells present in some animals. Which of the following cells can differentiate to perform different functions?

1. Choanocytes.
2. Interstitial cells.
3. Gastrodermal cells.
4. Nematocytes.

Define vital capacity. What is its significance?

The spread of living pteridophytes is limited and restricted to narrrow, geographical regions. Why?

Justify the following statements on the basis of external features:
Underground parts of a plant are not always roots.

Give two examples of heterosporous ferns. Why are they called so?

How are gibberellins useful in agriculture to improve productivity. Give any three points in support of your answer.

The following parts in our body has specific names in osteology. Write the name for each.

1. Knee cap.
2. Collar bone.
3. Skull.
4. Spine.
5. Shoulder bone.
6. Coxal bone.

Amino acids are substituted methanes. Justify why are they called a-amino acids?

Why are living organisms classified?

Rani was amazed to read about the layers and coverings in the plant. As her teacher taught her that like mammals, plants are also formed by various layers of tissues. Thus, forming the different plant system. As the epidermal tissue system forms the outermost covering of the body. She felt curious and asked her elder sister about the same, that how come this is possible. Her sister cleared all her doubts patiently.

1. From where it is derived?
2. Why are outer wall of some plants is cutinised?
3. In some cases, the cuticle is reinforced by a layer of wax. Explain the reason.
4. Extract the message from Rani's behavior.