Name the following:

(i) The exchange of chromatid parts between the maternal and the paternal chromatids of a pair of homologous chromosomes during meiosis.

(ii) The number of individuals inhabiting per unit area.

(iii) The immunity acquired by providing readymade antibodies from outside for treating certain infectious diseases.

(iv) The pollutants that cannot be broken down to simple and harmless products.

(v) The part of the brain that carries impulses from one hemisphere of the cerebellum to the other.

Choose the correct answer from each of the four options given below:

A plant cell may burst when:

1. Turgor pressure equalises wall pressure.
2. Turgor pressure exceeds wall pressure.
3. Wall pressure exceeds turgor pressure.
4. None of the above

Choose the correct answer from each of the four options given below:

The nephrons discharge their urine at the:

1. Urinary bladder
2. Urethra
3. Renal pelvis
4. Renal pyramid

Choose the correct answer from each of the four options given below:

Gigantism and Acromegaly are due to:

1. Hyposecretion of Thyroxine.
2. Hyposecretion of Growth hormone
3. Hypersecretion of Thyroxine
4. Hypersecretion of Growth hormone