Environmental Science and Ecology - Mock Test 54

Question 531

One of the major difficulties in the biological control of insect pests is that?

A) The predator develops a preference to other diets and may itself become a pest B) They do not always survive when transferred to a new environment C) The method is less effective as compared to the use of insecticides D) The practical difficulty in introducing the predator to specific area

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Question 532

Ecosystem receives nitrogen from outside through?

A) Biological nitrogen fixation B) Electrification of nigrogen C) Industries D) All the above

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Question 533

If we completely remove the decomposers from an ecosysters, its functioning will be adversely affected because?

A) Herbivores will not receive solar energy B) Rate of decomposition of other component will be very high C) Mineral movement will be blocked D) Energy flow will be blocked

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Question 534

Mark the incorrect statement with reference to carbon cycle?

A) Lime rocks contribute to CO2 of water B) Atmospheric CO2 gets dissolved in water C) CO2 is returned by combustion of fuel D) 75% of total carbon lies in geological component

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Question 535

The sulphate rocks are formed in ocean by leaching of?

A) FeS and Fe2S3 B) Organic sulphates and -SH C) Soluble inorganic sulphates D) All of these

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Question 536

The maximum amount of CO2 fixed by green plants by way of photosynthesis in a year is?

A) 9 x 1013 kg B) 8 x 1012 kg C) 9 x 1011 kg D) 8 x 1010 kg

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Question 537

Hydrological cycle is under the control of?

A) Grasslands B) Forests C) Planktons D) Epiphytes

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Question 538

According to Odum the light absorbed by the plant cover in terms of kcal/m2/day is?

A) 150 B) 1,500 C) 300 D) 3,000

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Question 539

The SO2 is returned to the atomsphere by?

A) Metabolism of producers B) Metabolism of consumers C) Both a & b D) Combustion of fuel

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Question 540

Which ecological cycle is directly driven by sunlight?

A) Hydrologic B) Phosphorus C) Nitrogen D) Sulphur

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