In biotic community, which of the following can be called protective device ?

• Mimicry

• Symbiosis

• Competition

• Parasitism

It is much easier for a small animal to run uphill than a large animal, because

• smaller animals have a higher metabolic rate

• small animals have a lower O₂ requirement

• the efficiency of muscles in large animals in less than in the small animals

• the efficiency of muscles in large animals in less than in the small animals

When does the growth rate of a population following the logistic model equal zero? The logistic model is given as dN/dt = rN(1-N/K)

• when N nears the carrying capacity of the habitat

• when N/K equals zero

• when death rate is greater than birth rate

• when death rate is greater than birth rate

Gause's principle of competitive exclusion states that

• Competition for the same resources excludes species having different food preferences

• No two species can occupy the same niche indefinitely for the same limiting resources

• Larger organisms exclude smaller ones through competition

• Larger organisms exclude smaller ones through competition

Age of tree can be estimated by

• Its height of girth

• biomass

• number of annual rings

• number of annual rings

An association of individuals of different species living in the same habital and having functional interactions is

• Ecological niche

• Biotic community

• Ecosystem

• Ecosystem

The osmotic expansion of a cell kept in water is chiefly regulated by

• mitochondria

• vacuoles

• plastids 

• plastids 

In which of the following interactions both partners are adversely affected?

• Competition

• Predation

• Parasitism

• Parasitism

9.

The following graph depicts changes in two populations (A and B) of herbivores in a grassy field A possible reason for these changes is that:

• both plant populations in this habitat decreased

• population B competed more successfully for food than population A

• population A produced more offspring than population B

• population A produced more offspring than population B

Consider the following four conditions (a - d) and select the correct pair of them as adaptation to environment in desert lizards.
The conditions:
I. Burrowing in soil to escape high temperature.
II. Losing heat rapidly from the body during high temperature
III. Bask in sun when temperature is low
IV. Insulating body due to thick fatty dermis

• I and III

• II and IV

• I and II

• I and II