Give biological reasons for the following :

Wooden frames of doors get jammed during the monsoon season.

Briefly explain the following terms:

(i) Genes.

(ii) Cytokinesis in plant cells.

(iii) Guttation.

(iv) Diabetes insipidus.

(v) Disinfectants.

The figure given below shows the epidermal cells of an onion bulb. This cell was then transferred to a drop of sugar solution.

(i) Draw a well labelled diagram of the epidermal cell as it would appear after immersion in a strong sugar solution.

(ii) What scientific term is used for the changes as shown in (i) above ?

(iii) What should be done to restore the cell back to its original condition ?

(iv) Give the scientific term for the recovery of the cell as a result of the step taken in (iii) above.

(v) Define the term osmosis.

Give biological reasons for the following :

Throat infections can lead to ear infections.