A lake which is rich in organic waste may result in
(1) increased population of aquatic organisms due to minerals

(2) drying of the lake due to algal bloom

(3) increased population of fish due to lots of nutrients

(4) mortality of fish due to lack of oxygen

The highest DDT concentration in aquatic food chain shall occur in 
(1) phytoplankton

(2) seagull

(3) crab

(4) eel

Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancers
(1) ozone

(2) ammonia 

(3) methane

(4) nitrous oxide

Joint Forest Management Concept was introduced in India during
(1) 1970s

(2) 1980s

(3) 1990s

(4) 1960s

A river with an inflow of domestic sewage rich in organic waste may result in

1. increased population of aquatic food web organisms

2. an increased production of fish due to biodegradable nutrients

3. death of fish due to lack of oxygen

4. drying of the river very soon due to algal bloom

The UN conference of Parties on climate change in the year 2012 was held at

1. Durban             

2. Doha

3. Lima                 

4. Warsaw

Increase in concentration of the toxicant at successive tropic levels is known as

1. biomagnification

2. biodeterioration

3. biotransformation

4. biogeochemical cycling

Acid rain is caused by increase in the atmospheric concentration of

1. SO₂ and NO₂

2. SO₃ and CO

3. CO₂ and CO

4. O₃ and dust

Eutrophication of water bodies leading to killing of fishes is mainly due to non-availability of

1. food

2. light

3. essential minerals

4. Oxygen

Which of the following is not one of prime health risks associated with greater UV

radiation through the atmosphere due to depletion of stratospheric zone?

1. Increased skin cancer

2. Reduced immune system

3. Damage to eyes

4. Increased liver cancer