(i) It has only cone cells and is the place of most distinct vision. 

(ii) A type of white blood cells, meant for eliminating the antigen (microbes and their toxins) by releasing antibodies. These are B and T-lymphocytes. 

(iii) It is a bundle of heart-muscles that fapidly transmit the cardiac impulse received from Ay node to all parts of the ventricles causing them to contract. 

(iv) Calyptra is a cone shaped structure that covers the root-tips and develops as a result of cclidivision by the meristem called calyptrogen in monocot roots.

 (v) Bulliform cells are large thin walled protruding epidermal cells present on the upper epidermis of leaves of many grasses. They lose water and become flaccid and help to roll up leaves to reduce the exposed surface in case of water deficiency. 

(vi) Quiescent centre is present in the centre of root-apex and functions as reserve meristem. Here divisions are very few. They can survive stress and provide cells to a regenerating meristem and helps in the recovery of roots after irradiation.