Unit Test: Our Environment | Science Class 10 PDF Download

Time: 1 hour

M.M. 30

Attempt all questions.

• Question numbers 1 to 5 carry 1 mark each.
• Question numbers 6 to 8 carry 2 marks each.
• Question numbers 9 to 11 carry 3 marks each.
• Question number 12 & 13 carry 5 marks each.

Q1: In a food chain, the third trophic level is always occupied by (1 Mark)
(a) carnivores
(b) herbivores
(c) decomposers
(d) producers

Q2: In the given food chain, if the amount of energy at the fourth trophic level (Hawk) is 5 kJ, what will be the energy available at the producer level (Grass)? (1 Mark)
Grass → Grasshopper → Frog → Snake → Hawk

(a) 5 kJ
(b) 50 kJ
(c) 500 kJ
(d) 5000 kJ

Q3: Depletion of ozone is mainly due to: (1 Mark)
(a) chlorofluorocarbon compounds
(b) carbon monoxide
(c) methane
(d) pesticides

Q4: Organisms of a higher trophic level which feed on several types of organisms belonging to a lower trophic level constitute the (1 Mark)
(a) food web
(b) ecological pyramid
(c) ecosystem
(d) food chain

Q5: Why are green plants called producers? (1 Mark)

Q6: List two biotic components of a biosphere. (2 Marks)

Q7: What is meant by biological magnification? (2 Marks)

Q8: What are decomposers? List two important roles they play in the environment. (2 Marks)

Q9: In the following food chain, 100 J of energy is available to the lion. How much energy was available to the producers?

Plants → Deer → Lion (3 Marks)

Q10: What does a trophic level represent in a food chain? State the position of autotrophs and herbivores in a food chain. (3 Marks)

Q11: “Our food grains such as wheat and rice, the vegetables and fruits and even meat are found to contain varying amounts of pesticide residues.” State the reason to explain how and why it happens. (3 Marks)

Q12: “Industrialisation has adversely deteriorated the environment.” Give four reasons in support of this statement. (5 Marks)

Q13: Define an ecosystem. Draw a block diagram to show the flow of energy in an ecosystem. (5 Marks)