Improvement in Food Resources — Science STD 9 — Question

Minamata human disease is caused by pollution of water by:

1. Cadmium.
2. Lead.
3. Mercury.
4. Arsenic.

Starfish belongs to phylum:

1. Mollura.
2. Coelenterata.
3. Arthropoda.
4. Echinodermata.

The longest cell in the human body is:

1. Nerve cell.
2. Muscle cell.
3. Liver cell.
4. Kidney cell.

The muscular tissue which function throughout the life continuously without fatigue is:

Which of the labeled parts of the cell is its controlling centre:

Fertilizers cause:

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

Soil erosion is caused due to:

1. Strong wind.
2. Heavy rains.
3. Keeping the fields fallow for a long.
4. All of these.

Smooth muscles occur in:

1. Uterus.
2. Artery.
3. Vein.
4. All the above.

When both crops and livestock are raised on the same farm, it is known as:

1. Mixed farming.
2. Mixed cropping.
3. Intercropping.
4. Crop rotation.

A cell will swell up if: