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10th Class - CBSE - Biology - 1304 Questions - 0 Concepts

Important Questions

Q1 Single Correct Hard
Which is the correct pair of biological magnification?
  • A. Water - $$0.0003$$ ppm
  • B. Small fishes - $$0.2$$ ppm
  • C. Zoo plaktery - $$0.4$$ ppm
  • D. Big fishes - $$2$$ ppm

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Q2 Single Correct Hard
Pesticides sprayed in the environment can threaten predators in the area, this can cause
  • A. Global warming
  • B. Eutrophication of lakes
  • C. Depletion of the ozone layer
  • D. Acid rain
  • E. Magnification in the food chain

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Q3 Subjective Hard
Describe the advantage of keeping the ecosystem healthy? 

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Q4 Single Correct Hard
Which of the following statements is not correct regarding biomagnification?

(i) Mercury accumulated by an organism cannot be metabolised.
(ii) In the process of biomagnification, concentration of DDT is increased at successive trophic levels.
(iii) Accumulation of cadmium can cause thinning of eggshells in birds.
(iv) DDT accumulation is a major cause of a reduced population of fish-eating birds.
(v) Biomagnification occurs only in the aquatic food chain
  • A. (i), (iii) and (v)
  • B. (iii) and (iv)
  • C. (i), (ii) and (iv)
  • D. (iii) and (v)

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Q5 Subjective Hard
Healthy ecosystems are the base of a wide range of ecosystem services, Justify.

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Q6 Single Correct Hard
Non-biodegradable pollutants are created by 
  • A. Nature
  • B. Excessive use of resources
  • C. Natural disasters
  • D. Humans

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Q7 Assertion & Reason Hard
ASSERTION

The loss of biologically useful energy as heat with every energy transfer in a food chain is a consequence of the second law of thermodynamics.

REASON

Energy does not remain trapped permanently in any organism, it is either passed on to higher trophic level or becomes available to detritivores and decomposers after the organism dies.

  • A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
  • B. Assertion is correct but Reason is incorrect
  • C. Both Assertion and Reason are incorrect
  • D. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

Asked in: Biology - Our Environment


1 Verified Answer | Published on 07th 09, 2020

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Q8 Single Correct Hard
Which of the following statements about the depletion of ozone layer is correct?
  • A. Oxides of nitrogen also do not react with ozone in stratosphere.
  • B. The problem of ozone depletion is more serious at poles because ice crystals in the clouds over poles act as catalyst for photochemical reactions involving the decomposition of ozone by $$Cl$$ and $$ClO$$ radicals.
  • C. Freons, chlorofluorocarbons, are inert chemically, they do not react with ozone in stratosphere.
  • D. The problem of ozone depletion is less serious at poles because $$NO_2$$ solidifies and is not available for consuming $$ClO$$ radicals.

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Q9 Single Correct Hard
The given figure represents biomagnification of DDT in an aquatic food chain. Select the incorrect statement regarding this -
  • A. When agricultural fields are sprayed with DDT, it is carried by runoff water into nearby aquatic bodies.
  • B. Increased concentration of DDT in birds affects calcium metabolism due to which egg shells become thin and break before maturity.
  • C. None of these
  • D. River water may have a very low concentration of DDT, but the concentration of DDT, which is still suitable for consumption by human beings.

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Q10 Assertion & Reason Hard
ASSERTION

A network of food chains of an ecosystem is called food web.

REASON

Kite cannot be part of food web.

  • A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
  • B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
  • C. Both Assertion and Reason are incorrect
  • D. Assertion is correct but Reason is incorrect

Asked in: Biology - Our Environment


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Questions 122475
Subjects 10
Chapters 93
Enrolled Students 65
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