Tissues — Science STD 9 — Question

Eutrophication results in reduction of:

1. Dissolved hydrogen.
2. Dissolved oxygen.
3. Mineral salts.
4. Dissolved nitrate.

Colourless plastids are known as:

1. Leucoplasts.
2. Chromoplasts.
3. Chloroplasts.
4. None of the above.

Pollution of water is caused by:

1. Industrial effluents.
2. Sewage.
3. Farm runoff.
4. All of these.

Explain ozone layer, its depletion and effects of ozone depletion.

The fungus disease causing maximum death of poultry bird is:

1. Coryza
2. Pullorum
3. Rickets
4. Aspergillosis

Fertilizers cause:

1. Eutrophication of water bodies.
2. Killing of most microorganisms.
3. Destruction of crumb structure of soil.
4. All the above.

Biosphere occurs:

1. In lithosphere.
2. In lithosphere and hydrosphere.
3. At place of interaction of lithosphere, hydrosphere and atmosphere.
4. In atmosphere and hydrosphere.