No. of Printed Pages: 6 ILSE-021
BACHELOR OF SCIENCE (B.Sc.)
Term-End Examination

December, 2016
U2S94 Time: 2 hours LIFE SCIENCE LSE-02 ECOLOGY Maximum Marks: 50

Note: Question no. 1 is compulsory. Attempt any four questions from questions no. 2 to 6.

1. Define the following terms: 5

Secondary consumer

Field capacity of soil

Mortality

Sludge

Wind

Fill in the blanks: 3

On cooling, water molecules come which makes the water dense.

Oxygen content of hypolimnion zone of a water body is low due to its utilization by processes.

Fidelity refers to the degree to which a is restricted in its occurrence to a particular kind of community.

State whether the given statements are True or False: 2

If a population is growing at 2 percent growth rate, then it will double in 35 years.

Thiobacillus reduces H2S to SO4

Sum of all genes of an individual is called gene pool.

Vegetations of ecotones are highly specialized.

2. Differentiate between any four of the following: 10

Phanerophytes and Chamaephytes

Autecology and Synecology

Summer stratification and Winter stratification

Detritus food chain and Auxiliary food chain

Mesophytes and Xerophytes

3. Answer the following:

Briefly discuss the causes of air pollution. 5

How do organisms adapt to extreme temperatures? 5

4. Write a brief account of defence mechanisms in plants. 5

"Domestication is a potential threat to wildlife." Comment. 5

5. Briefly discuss the chemical properties of soil. 5

Discuss the various types of grasslands. Write their economic importance. 2+3

6. Write short notes on any four of the following: 10

Population Growth Curve

Denitrification

Carrying Capacity

Role of urbanization on degradation of ecosystem

Phosphorus Cycle