The basic structural unit of human chromosome is :

1. Nucleotide
2. Nucleic acid
3. Nucleoside
4. Nucleosome

The phenotypic ratio in F₂ generation of a monohybrid cross is :

1. 1:3
2. 1:2:1
3. 3:1
4. 9:3:3:1

Name the following :

(i) The organelle which initiates cell division.

(ii) The genetic constitution of an organism.

(iii) The plastid which contains coloured pigments (yellow/orange/red, etc.)

(iv) A solution whose concentration is greater than that of the cell sap.

(v) The biological process which is the starting point of the food chain.

Arrange and rewrite the terms in each group in the correct order so as to be in a logical sequence beginning with the term that is underlined (highlighted).

(i) Prophase, Telophase, Anaphase, Metaphase

(ii) Kidney, Urethra, Ureter, Urinary bladder

(iii) Right ventricle, Lungs, Pulmonary vein, Pulmonary artery

(iv) Ear pinna, Membranous labyrinth, Ear ossicles, Auditory canal

(v) Stimulus, Effector, Receptor, CNS.