Which one of the following has the largest population in a food chain?

1

(a)

Producers

(b)

Primary consumers

(c)

Secondary consumers

(d)

Decomposers

Which of the following is expected to have the highest value (gm/m²/yr) in a grassland ecosystem?

1

(a)

Tertiary production

(b)

Gross production

(c)

Net production

(d)

Secondary production

Maximum absorption of rainfall water is done by 

1

(a)

tropical deciduous forest

(b)

tropical evergreen forest

(c)

tropical savannah

(d)

scrub forest

Stability of ecosystem depends upon

1

(a)

primary productivity

(b)

interchange between producers and consumers

(c)

number of producers

(d)

number of consumers

Which one of the following is considered as pioneer community in xerarch?

1

(a)

annual herb

(b)

perennial herb

(c)

scrub stage

(d)

forest stage

(e)

lichen

Write the basis on which an organism occupies a space in its community/natural surroundings.

1

(a)

Their feeding relationship with other organisms.

Mention the role of pioneer species in primary succession on rocks.

1

(a)

Lichens are the pioneer species in the succession on rocks; they secrete acids to dissolve the rock and help in weathering and soil formation and pave way to bryophytes.

How is the primary productivity in an ecosystem determined?

1

(a)

Net Primary Productivity (NPP)
Net primary productivity refers to the biomass/organic matter available at the producer level to the primary consumers,i.e. GPP-Respiratory losses.
Gross Primary Productivity (GPP)
Gross primary productivity is the rate of production of biomass/organic matter by producers during photosynthesis.

Justy the pitcher plant as a producer.

1

(a)

The pitcher plant bears chlorophyll and is photosynthetic;it depends on insects only for its nitrogen supply and hence is a producer.

Justify the pitcher plant as a producer.

1

(a)

It is green, chloropohyllous and manufactures food through photosynthesis.

Explain with the help of two examples,how the pyramid of number and the pyramid of biomass can look inverted.

2

(a)

Distinguish between production and decomposition.

2

(a)

Distinguish between litter and dertritus.

2

(a)

Distinguish between grazing food chain and detritus food chain.

2

(a)

Make a table showing typical climatic conditions in major forest types in India.

2

(a)

Why are green algae not likely to be found in the deepest strata of the ocean?

3

(a)

In a pyramid of biomass drawn below, name the two crops:
(i) one which is supported and
(ii) the one which supports.In which ecosystem is such a pyramid found?

3

(a)

Construct labelled grazing and detritus food chains with minimum three trophic levels each.

3

(a)

What is a food web?

3

(a)

Describe the role of living organisms in the cycle .

5

(a)

(a) Draw an ideal pyramid of energy upto four trophic levels,where 10,00,00 J are available  from sunlight to the primary producer.Indicate the amount of energy available at each trophic level.
(b) Why is pyramid of energy always upright?Explain
(c) Mention the limitation of an ecological pyramid.

5

(a)

Write a short note on pyramid of numbers and pyramid of biomass.

5

(a)