Advertisement

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

603 Views

Advertisement

The Indian rhinoceros is a natural inhabitant of which one of the Indian states?

  • Uttarakhand

  • Uttar Pradesh

  • Himachal Pradesh

  • Himachal Pradesh


D.

Himachal Pradesh

Indian rhinoceros (Rhinoceros unicornis) is a natural inhabitant of Assam is India. It is now protected in Kaziranga National Park situated at sib sager in Jorhat district of Assam.

508 Views

Which one of the following types of organisms occupy more than one trophic level in a pond ecosystem?

  • Phytoplankton 

  • Fish

  • Zoonplankton

  • Zoonplankton


B.

Fish

In a pond ecosystem fishes occupy the more than one trophic levels.

419 Views

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


B.

A

B

C

D

Dentirificiation

Ammonification

Plants

Animals

A- Denitrification

B-Ammonification

C- Plants

D-Animals

312 Views

Which one of the following is being tried in India as a biofuel substitute for fossil fuels

  • Jatropha

  • Azadirachta

  • Musa

  • Musa


A.

Jatropha

Biofuels are substances of biological origin which are used for the production of heat and another form of energy. Often biologically generated hydrogen, methane, ethanol, butanol and diesel are referred to as biohydrogen, biomethane, bioethanol, biobutanol and biodiesel respectively. Petro plans are the plants which can yield a large amount of latex having long chained liquid hydrocarbon, eg, Jatropha, Euphorbia (family-Euphorbiaceae) and other members of Euphorbiaceae, Asclepiadaceae, Apocyanaceae. 

The wood used as a source of energy is called fuel wood. The good fuelwood should be free from resin, much smoke and offensive odours. Hardwood is generally good fuel wood, Casuarina, Azadirachta, Dalbergia, Terminalia.

324 Views

Advertisement