Science (English Medium) Class 11 - CBSE Question Bank Solutions for Biology

A plant species shows several morphological variations in response to altitudinal gradient. When grown under similar conditions of growth, the morphological variations disappear and all the variants have common morphology. What are these variants called?

How do you prepare your own herbarium sheets? What are the different tools you carry with you while collecting plants for the preparation of a herbarium? What information should a preserved plant material on the herbarium sheet provide for taxonomical studies?

What are taxonomical aids? Give the importance of herbaria and museums. How are Botanical gardens and Zoological parks useful in conserving biodiversity?

A student of taxonomy was puzzled when told by his professor to look for a key to identify a plant. He went to his friend to clarify what ‘Key’ the professor was refering to? What would the friend explain to him?

Organisms living in salty areas are called as ______.

What is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement?

Make a list of algae and fungi that have commercial value as source of food, chemicals, medicines and fodder.

In Opuntia the stem is modified into a flattened green structure to perform the function of leaves (i.e., photosynthesis). Cite two other examples of modifications of plant parts for the purpose of photosynthesis.

Name the body part modified for food storage in the following:

Colocasia ______.

Name the body part modified for food storage in the following:

Potato ______.

Name the body part modified for food storage in the following:

Turmeric ______.

Name the body part modified for food storage in the following:

Gladiolus ______.

Name the body part modified for food storage in the following:

Ginger ______.

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

Cucumber

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

Pumpkins

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

Grapevine

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

Watermelons

Tendrils of grapevines are homologous to the tendril of pumpkins but are analogous to that of pea. Justify the above statement.

Describe various stem modifications associated with food storage, climbing and protection.

Stolon, offset and rhizome are different forms of stem modifications. How can these modified forms of stem be distinguished from each other?