Secondary producers are

1

(a)

Herbivores

(b)

Producers

(c)

Carnivores

(d)

None of these

Secondary producers are

1

(a)

Herbivores

(b)

Producers

(c)

Carnivores

(d)

None of the above

Which of the following represents the sedimentary type of nutrient cycle?

1

(a)

Nitrogen

(b)

Carbon

(c)

Phosphorus

(d)

Oxygen

Given is one of the types of ecological pyramids. This type represents

1

(a)

pyramid of numbers in a grassland

(b)

pyramid of biomass in a fallow land

(c)

pyramid of biomass in a lake

(d)

energy pyramid in a spring

Term ecosystem was given by

1

(a)

Odum

(b)

Haeckel

(c)

Tansley

(d)

Mobius and Forbes

It is estimated that about 85% of the earth's photosynthetic activity is carried out by

1

(a)

trees

(b)

savannahs

(c)

phytoplanktons

(d)

herbaceous plants

In an ecosystem, the cycling of nutrients is known as

1

(a)

geological cycle

(b)

chemical cycle

(c)

geochemical cycle

(d)

biogeochemical cycle

In primary succession on rocks, the pioneer species are usually

1

(a)

alagae

(b)

fungi

(c)

lichens

(d)

bryophytes

Of the total incident solar radiation the proportion of PAR is

1

(a)

about-70%

(b)

about 60%

(c)

less than 50%

(d)

more than 80%

Which one of the following statements for the pyramid of energy is incorrect?

1

(a)

its base is broad 

(b)

it shows energy content of different trophic level organisms

(c)

it is inverted in shape

(d)

it is upright in shape

Write a difference between net primary productivity and gross productivity

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.

Define  ecological succession.

1

(a)

Ecological succession  is a community controlled phenomenon, in which the structure and composition of communities change in an orderly and sequential manner, leading ultimately to the establishment of a climax community.

Justify the pitcher plant as a producer.

1

(a)

It has chlorophyII pigments in its parts and is, therefore, capable of photosynthesis.

List any two ways of measuring the standing crop of a trophic level.

1

(a)

Two ways of measuring the standing crop of a trophic level are:
(i) Biomass of living organisms
(ii) The number in a unit area.

Differentiate between primary and secondary succession.

2

(a)

What is an incomplete ecosystem? Explain with the help of suitable example.

2

(a)

Explain the terms standing crop, biomass and standing state.

2

(a)

What materials the various subdivisions of the biosphere supply to the organisms?

2

(a)

Differentiate between the two different types of pyramids of biomass with the help of one example each.

3

(a)

Give two examples of each of:
(i) Terrestrial ecosystem
(ii) Aquatic ecosystem
(iii) Man-made ecosystem

3

(a)

What is humus?Mention its properties.

3

(a)

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

3

(a)

According to the 10% law given by Lindeman, only 10% of the energy is transferred to the next trophic level.
(i) Name the process by which an organism produces energy.
(ii) What is the most common substrate used in this pathway?
(iii) Which biomolecule is also known as energy currency of the cell?

3

(a)

List the different steps and state their role in the process of decomposition in an ecosystem.

5

(a)

Describe a pond as an ecosystem.

5

(a)