Secondary metabolites such as nicotine, strychnine and caffeine are produced by plants for their:

NEET-(Sept)2020 Organisms-and-Populations [class-xii ]

• Nutritive value
• Growth response
• Defence action
• Effect on reproduction
Correct Option: C  [ Defence action ]

Remark:

Match the trophic levels with their correct species examples in grassland ecosystem.

NEET-(Sept)2020 Ecosystem [class-xii ]

• (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
• (A)-(III), (B)-(II), (C)-(I), (D)-(IV)
• (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
• (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
Correct Option: A  [ (A)-(II), (B)-(III), (C)-(IV), (D)-(I) ]

Remark:

In relation to Gross primary productivity and Net primary productivity of an ecosystem, which one of the following statements is correct?

NEET-(Sept)2020 Ecosystem [class-xii ]

• Gross primary productivity is always less than net primary productivity.
• Gross primary productivity is always more than net primary productivity.
• Gross primary productivity and Net primary productivity are one and same.
• There is no relationship between Gross primary productivity and Net primary productivity.
Correct Option: B  [ Gross primary productivity is always more than net primary productivity. ]

Remark:

The rate of decomposition is faster in the ecosystem due to following factors except:

NEET-(Oct)2020 Ecosystem [class-xii ]

• Detritus rich in sugars
• Warm and moist environment
• Presence of aerobic soil microbes
• Detritus richer in lignin and chitin
Correct Option: D  [ Detritus richer in lignin and chitin ]

Remark:

Which of the following statements is incorrect?

NEET-(Oct)2020 Ecosystem [class-xii ]

• Biomass decreases from first to fourth trophic level
• Energy content gradually increases from first to fourth trophic level
• Number of individuals decreases from first trophic level to fourth trophic level
• Energy content gradually decreases from first to fourth trophic level
Correct Option: B  [ Energy content gradually increases from first to fourth trophic level ]

Remark:

Which of the following statements is incorrect regarding the phosphorus cycle?

NEET-(Oct)2020 Ecosystem [class-xii ]

• Phosphates are the major form of phosphorus reservoir
• Phosphorus solubilising bacteria facilitate the release of phosphorus from organic remains
• There is appreciable respiratory release of phosphorus into atmosphere
• It is sedimentary cycle
Correct Option: C  [ There is appreciable respiratory release of phosphorus into atmosphere ]

Remark:

In the following in each set a conservation approach and an example of method of conservation are given:
A. In situ conservation - Biosphere Reserve
B. Ex situ conservation - Sacred groves
C. In situ conservation - Seed bank
D. Ex situ conservation - Cryopreservation
Select the option with correct match of approach and method:

NEET-(Oct)2020 Biodiversity-and-Conservation [class-xii ]

• (A) and (C)
• (A) and (D)
• (B) and (D)
• (A) and (B)
Correct Option: B  [ (A) and (D) ]

Remark:

Which of the following regions of the globe exhibits highest species diversity?

NEET-(Sept)2020 Biodiversity-and-Conservation [class-xii ]

• Western Ghats of India
• Madagascar
• Himalayas
• Amazon forests
Correct Option: D  [ Amazon forests ]

Remark:

Air (Prevention and Control of Pollution) Act was amended in 1987 to include among pollutants:

NEET-(Oct)2020 Environmental-Issues [class-xii ]

• Vehicular exhaust
• Allergy causing pollen
• Noise
• Particulates of size 2.5 micrometer or below
Correct Option: C  [ Noise ]

Remark:

Which of the following is put into Anaerobic sludge digester for further sewage treatment?

NEET-(Sept)2020 Environmental-Issues [class-xii ]

• Primary sludge
• Floating debris
• Effluents of primary treatment
• Activated sludge
Correct Option: D  [ Activated sludge ]

Remark: