A high density of elephant population in an area can result in:
Mutualism
Intraspecific competition
Interspecific competition
Predation on one another
Niche overlap indicates:
Active cooperation between two species.
Two different parasites on the same host.
Sharing of one or more resources between the two species.
Mutualism between two species.
Which one of the following pairs is mismatched ?
Savanna ---- Acacia trees
Prairie - Epiphytes
Tundra - Permafrost
Coniferous forest - Evergreen trees
Annual migration does not occur in the case of:
Salmon
Siberian crane
Salamander
Arctic tern
Montreal protocol aims at:
Reduction of ozone depleting substances
Biodiversity conservation
Control of water pollution
Control of CO2 emission
Which of the following is NOT used for disinfection of drinking water ?
Phenyl
Chloramine
Chlorine
Ozone
What is BOD ?
The amount of O2 utilized by organisms in water
The amount of O2 utilized by micro-organisms for decomposition
The total amount of O2 present in water
All of the above
Recently Government of India has allowed mixing of alcohol in petrol. What is the amount of alcohol permitted for mixing in petrol ?
2.5%
10 - 15 %
10 %
5%
A lake near a village suffered heavy mortality of fishes within a few days . Consider the following reasons for this:
(1) Lots of urea and phosphate fertilizer were used in the crops in the vicinity .
(2) The area was sprayed with DDT by an aircraft .
(3) The lake water turned green and stinky .
(4) Phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis .
Which two of the above were the main causes of fish mortality in the lake?
2, 3
3, 4
1, 3
1, 2
In a terrestrial ecosystem such as forest, maximum energy is in which trophic level ?
T1
T2
T3
T4
