You are given leech, Nereis, Scolopendra, prawn and scorpion; and all
have segmented body organisation. Will you classify them in one group? If
no, give the important characters based on which you will separate these
organisms into different groups.
Define the terms and give one example of each
(a) Bilateral symmetry
(b) Coelom
(c) Triploblastic
How many images of a candle will be formed if it is placed between two
parallel plane mirrors separated by 40 cm?
What is the angle of incidence of a ray if the reflected ray is at an angle of
90° to the incident ray?
Thallophyta, bryophyta and pteridophyta are called as ‘Cryptogams’.
Gymnosperms and Angiosperms are called as ‘phanerogams’. Discuss why?
Draw one example of Gymnosperm.
Gurmit wanted to perform Activity 13.8 using a laser torch. Her teacher
advised her not to do so. Can you explain the basis of the teacher’s advise?