Natural Resources — Science STD 9 — Question

Ozone hole was discovered in:

1. 1992
2. 1985
3. 1995
4. 1998

By the process of lignification, cell becomes:

When a cell is placed in a medium, and it increases in size, the external medium is:

Some crops are grown in Kharif season, from the month of:

Endoplasmic reticulum is absent in:

Gundhi bug is a pest of:

1. Sugarcane
2. Cotton
3. Rice
4. Wheat

Algae belong to:

1. Thallphytes.
2. Bryophytes.
3. Pteridophytes.
4. All of the above.

Heart muscles are:

1. Voluntary and striated.
2. Involuntary and striated.
3. Voluntary and rnultinucleate.
4. Involuntary, striated and uninucleate.

Cattle husbandry is done for the following purpose.

1. Milk production.
2. Agricultural work.
3. Meat production. 
4. Egg production.

1. (i), (ii) and (iii)
2. (ii), (iii) and (iv)
3. (iii) and (iv)
4. (i) and (iv)

Heat generating cells of animals are: