Lichens are well known combination of an alga and a fungus where fungus has

1

(a)

an epiphytic relationship with the alga

(b)

a parasitic relationship with the alga

(c)

a symbiotic relationship with the alga

(d)

a saprophytic relationship with alga

What is a keystone species?

1

(a)

A common species that has plenty of biomass, yet has a fairly low impact on the community's organization

(b)

A race species that has minimal impact on the biomass and on other species in the community

(c)

A dominant species that constitutes a larger proportion of the biomass and which affects many other species

(d)

A species which makes up only a small proportion of the total biomass of community, yet has a huge impact on the community's organization and survival.

Animals have the innate ability to escape from predation. Examples for the same are given below. Select the incorrect example.

1

(a)

colour change in chamaeleon

(b)

enlargement of body size by swallowing air in puffer fish

(c)

poison fangs in snakes

(d)

melanism in months

Select the statement which explains best parasitism.

1

(a)

One organism is benefited.

(b)

Both the organisms are benefitted

(c)

One organism is benefitted, other is not affected

(d)

One organism is benefited, other is affected.

Keystone species deserve protection because these

1

(a)

are capable of surviving in harsh environmental conditions

(b)

indicate presence of certain minerals in the soil 

(c)

have become rare due to overexploitation

(d)

play an important role in supporting other species.

Popluation density of terrestrial organism is measured in terms of individual per

1

(a)

meter³

(b)

meter⁴

(c)

meter

(d)

meter²

The amount of fresh water of the earth frozen as polar or glacial ice is

1

(a)

0.5%

(b)

0.02%

(c)

0.01%

(d)

1.97%

(e)

2.5%

Niche is defined as the 

1

(a)

position of species in a community in relation to other species

(b)

place where organism lives

(c)

place where organism lives and performs its duty

(d)

place where population perform their duties

A protozoan reproduces by binary fission. What will be the number of protozoans in its population after six generations?

1

(a)

128

(b)

24

(c)

64

(d)

32

Some organism are tolerant to a narrow range of salinity

1

(a)

eurhaline

(b)

stenohaline

(c)

neither(a) nor (b)

(d)

saline

Name the type of interaction between a whale and the barnacles growing on its back.

1

(a)

Commensalism.

Give one example where animal-plant interaction involves co-evolution.

1

(a)

The mediterranean orchid, Ophrys and its pollinators (bumble bees and bees) have co-evolved.

What does ecological niche of an organism represent?

1

(a)

Ecological niche of an organism represents the range of conditions it can tolerate, the resources it utilises and its functional role in the ecosystem.

What does stratification of community depict?

1

(a)

Stratification of a community depicts vertical layering of vegetation.

Which bacteria live on the human skin?

1

(a)

Staphylococcus aureus

Explain why very small animals are rarely found in polar region.

2

(a)

Distinguish between ectotherms and endotherms.

2

(a)

Differentiate between immigration and emigration.

2

(a)

What is Resource partitioning? Give an example.

2

(a)

Define heliophytes and sciophytes. Name plant from your locality that is either heliophyte or sciophyte.

2

(a)

Explain brood parasitism with the help of an example.

3

(a)

Name six major terrestrial biomes of the world.

3

(a)

Describe any three reproductive strategies that organisms have evolved in relation to a particular set of selective pressures.

3

(a)

How do snails, seeds, bears, zooplanktons, fungi and bacteria adapt to conditions unfavourable for their survival?

3

(a)

Define commensalism.  Describe any four examples.

5

(a)

A population od Paramecium caudatum was grown in a culture medium. After 5 days the culture medium became overcrowded with Paramecium and had depleted nutrients.
What will happen to the population and what type of growth curve will the population attain?Draw the growth curve.

5

(a)