DDT residues are rapidly passed through food chain causing biomagnification because DDT is
liposoluble
moderately toxic
non-toxic to aquatic animals
non-toxic to aquatic animals
A.
liposoluble
Many pesticides, such as DDT, aldrin and dieldrin are accumulated in the environment. They are fat soluble and generally non-biodegradable, They get incorporated into the food chain and ultimately deposited in the fatty tissue of animals and humans. In the food chain because of their build up, they get magnified in the higher trophic levels called biological magnification. The phenomenon of biological magnification is also reported of certain other pollutants such as heavy metals.eg, mercury, copper and radioactive substances as strontium-90
Which domestic sewage mixes with river water
small animals like rats will die after drinking river water
the increased microbial activity releases micronutrients such as iron
the increased microbial activity uses up dissolved oxygen
the increased microbial activity uses up dissolved oxygen
An imporved variety of trasgenic basmati rice
does not require chemical fertilisers and growth hormones
gives high yield nd is rich in vitamin-A
is completely resistant to all insect pests and diseases of paddy
is completely resistant to all insect pests and diseases of paddy
The Indian rhinoceros is a natural inhabitant of which one of the Indian states?
Uttarakhand
Uttar Pradesh
Himachal Pradesh
Himachal Pradesh
The biomass available for consumption by the herbivores the decomposers is called
net primary productivity
secondary productivity
standing crop
standing crop
The breakdown of detritus into smaller particles by earthworm is a process called
humification
fragmentation
mineralisation
mineralisation
Study the four statements (1-4) given below and select the two correct one out of them.
1. A lion eating a deer and a sparrow feeding on grain are ecologically similar in being consumers
2.Predator starfish pisaster helps in maintaining species diversity of some invertebrates
3.Predators ultimately lead to the extinction of prey species
4.Production of chemicals such as nicotine, strychnine by the plants are metabolic disorders
The two correct statements are
(2) and (3)
(3) and (4)
(1) and (4)
(1) and (4)
Both, hydrarch and xerarch successions lead to
medium water conditions
xeric conditions
highly dry conditions
highly dry conditions
Study the cycle shown below and select the option which gives correct words for all the four blanks A, B, C and D.
|
A |
B |
C |
D |
|
Nitrification |
Ammonification |
Animals |
plants |
|
A |
B |
C |
D |
|
Dentirificiation |
Ammonification |
Plants |
Animals |
|
A |
B |
C |
D |
|
Nitrification |
Denitrification |
Animals |
Plants |
|
A |
B |
C |
D |
|
Nitrification |
Denitrification |
Animals |
Plants |
Which one of the following types of organisms occupy more than one trophic level in a pond ecosystem?
Phytoplankton
Fish
Zoonplankton
Zoonplankton
