Page 1 - 4.Home Assignment II (Worksheet)-Ozone layer Depletion

SAI International School
Subject- Biology, Class- X
Chapter- Our Environment
Subtopic- Ozone Layer and its Depletion,
Managing the Garbage that We Use
Module-32
Home Assignment-II
Worksheet-I

1. Which of the following ecological pyramids is always straight?
(a) Pyramid of numbers
(b) Pyramid of biomass
(c) Pyramid of energy
(d) All of the above

2. The thinning of ozone layer allows more UV radiations to pass through it and
these may cause in humans -
(a) Incidences of skin cancer
(b) Increased incidences of cataract in eyes
(c) Both (a) and (b)
(d) Neither (a) nor (b)

3. Herbivores, in a grassland ecosystem represent –
(a) First trophic level
(b) Second trophic level
(c) Third trophic level
(d) Fourth trophic level

DIRECTION: The following questions (4 and 5) consist of two statements -
Assertion (A) and Reason (R). Answer these questions selecting the
appropriate option given below:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both Assertion and Reason are false.

Q.4 Assertion: A network of food chains existing together in an ecosystem is
known as food web.
Reason: An animal like kite cannot be a part of food web.

Q.5 Assertion: UV radiations cause photodissociation of ozone into O2 and O thus
causing damage to the stratospheric ozone layer.
Reason: Ozone hole is resulting in global warming and climatic change.

Q.6 How can you help in reducing the problem of waste disposal? Give any three
methods.