Fill in the blank.

The process by which an organism tries to maintain the constancy of its internal environment is called  ---------------------.

Adaptations are the attributes of the organisms which enable them to survive and reproduce in its habitat.Give two adaptations each for the organisms given below.

1.Kangaroo rat

2.Desert plants like Opuntia

3.Polar seals

Identify the methods by which the following organisms tide over unfavourable conditions.

a) Snails  b) Seed  c) Bears  d) Zooplankton  e) Fungi  f) Bacteria

Response of organisms to abiotic stress involves different methods.Write any three such responses with suitable examples

Observe the relationship of the first pair and fill in the blank.

a) Tolerant to a wide range of salinity : Euryhaline

     Restricted to a narrow range of salinity  : ..............................    

Differentiate  Eurythermal and  Stenothermal  organisms.

Regional and local variations within each biome lead to the formation of a wide variety of habitats.

            a) Name  any  two  major biomes seen in  India?                                         

          b)  What are the key elements that lead to variations in the
physical and chemical conditions of different habitats ?

Very small animals are rarely found in polar region.Justify?

Examine the following equation related to exponential growth.

N _t = N_oe^rt

What is r ,N_t, N_o and e  stand for?

A population has certain attributes that an individual organism does not.Which are they?

Notice the organisms given below.

Monarch butterfly and bird.

a) Name the type of population interaction between the two

b) Put + ,- aganist each organism based on the interaction.

Match the items of column A with column B

                         A                                                                               B

1. Cuckoo and crow                                          (i) Commensalism
2. Mycorrhizae                                                   (ii) Brood Parasitism
3. Balanus and Chathamalus                            (iii) Predation
4. Sea anemone and Clown fish                       (iv) Competition

                                                                                (v) Mutualism

Observe the age pyramids a  and b given below.

Name the pyramids represented by a  and b. Write the significance of age pyramid.

Observe the population growth curves 'a' and 'b' shown in the graph given below

Name them and write the equation for calculating growth rate( 'dN/dt' ) of 'a' and 'b'.

Explain why interaction between sea anemone and clown fish is considered as an example for commensalism?

Cattle egret and grazing cattle in close association is an example of commensalism. Substantiate.

What do you mean by brood parasitism.Give an example.

Differentiate  ectoparasites and endoparasites

 Parasites have evolved special adaptations in accordance with their life styles. Write any four  for such adaptations.

 Some  interspecific interactions between organisms are given in the table .(Hint : '+' for beneficial,' - '  for detrimental and  '0' for neutral interaction.)

  Name the interactions a, b, c and d.

Observe the flow chart given below.

Identify the factors represented by I and D. Explain how they influence population density (N).

Fill in the blank.

The nature's way of transferring energy fixed by plants to higher trophic levels is by ...................................

List out any two important roles of predators in a population.

Fill in the blank.

An important area of ecology that links ecology to population genetics and evolution is----------------------.

.Persons living in high altitudes have adaptations to compensate low oxygen availability in high altitudes. Write any two such adaptations.

Plants have evolved a variety of morphological and chemical defences against herbivores.Write such a morphological and chemical defence mechanism with examples.

Notice the equation given below..

a) What do N,r and K stand for?

b) Name the kind of population growth described by the above equation.

Choose the correctly matched pair.

A. Mutualism             - One species is benefited and the other is harmed

B. Commensalism  - Both the species are benefited

C. Amensalism     - One species is harmed and the other is neither       benefited nor harmed

Match the items of column A with B.

       A                                                              B

a. Kangaroo rat                                         i)Bask in the sun

b.Polar Seal                                                       ii) Diapause

c. Opuntia                                                 iii) Blubber

d. Desert Lizard                                       iv) Concentrated urine

                                                                     v) Sunken stomata

Fill in the blank.

Association between fungi and the roots of higher plants is known as ------------------

Choose  the correct answer.

An orchid named Ophrys  employs ..................................... for pollination.

a. Camouflage

b. Sexual deceit

c. Diapause

d. Brood parasitism

Observe the relationship between  the first two terms and fill in the blank.

Ticks on dogs :::  Parasitism

Lichen              :::   ................................