Plant Kingdom — BIOLOGY STD 11 Science — Question

Kavita (student of class VIII) returned from the school and started counting her teeth. She felt surprised and counted her teeth two more times, but each time she count, she found her teeth to be 28 in number. Then, she started counting his younger brother (student of class I) teeth and found them to 20 in number. She rushed to his father who was a dentist and told him, that her teacher taught her that human beings have 32 teeths. But she has only 28 and his brother has 20. Her father explained that number of teeth are related to the age of a child and also told her about diphyodont and heterodont dentition.

1. How is number of teeth related to the age of a child?
2. At what age, a person gets 32 teeth?
3. What do you understand by heterodont and diphyodont?
4. What values are reflected from Kavita's behaviour?

What was the disadvantages of artificial system of classification?

How the study of anatomy is useful to us?

What is the function of Henle's loop?

When and where does reduction division take place in the life cycle of a liverwort, a moss, a fern, a gymnosperm and an angiosperm?

Explain briefly the alternation of generation in bryophytes.

Plants manage to grow under limited water supply without compromising on metabolic activities. How?

Assimilation of atmospheric free nitrogen does not occur directly in the higher plants. If agree justify.

What is the difference between fibrous roots and adventitious roots?

Tendrils are found in the following plants. Identify whether they are stem tendrils or leaf tendrils.

1. Cucumber.
2. Pea.
3. Pumpkin.
4. Grapevine.