NCERT Book Class 11 Biology Model Answers To Descriptive Questions

MODEL ANSWERS

TO DESCRIPTIVE QUESTIONS

This chapter deals with model answers to all types of descriptive questions such as Very Short Answer (VSA) type questions, Short Answers (SA) type questions
and Long Answer (LA) type questions. The questions are randomly selected from different units, the answers are suggestive and written to provide approach and way of presentation. They are categorised under three headings as follows:

ANSWERS TO VSA TYPE QUESTIONS

1. Identify the phylum in which adults exhibit radial symmetry and larva exhibit bilateral symmetry.

Ans. In phylum echinodermata, adults show radial symmetry whereas larvae show bilateral symmetry.

2. What is the importance of pneumatic bones and air sacs in Aves?

Ans. Pneumatic bones in Aves keep the body light and thus help in flight. Air sacs help in respiration and buoyancy.

3. What is metagenesis? Mention an example which exhibits this phenomenon.

Ans. Alteration of generation is known as metagenesis. Obelia exhibits this phenomenon.

4. Which segments in earthworm are covered by a prominent dark band orclitellum?

Ans. 14th - 16th segments

Please refer to attached file for NCERT Class 11 Biology Model Answers To Descriptive Questions