Question

(a) Name a terminal method to prevent pregnancy in humans.
(b) Describe the procedure of the terminal method carried in human male and female.

Answer 1

(a) Surgical methods / Sterilisation = 1
(b) Males - Vasectomy , a small part of vas deferens is removed or tied up through a small incision on the scrotum = ½ + ½ Females - Tubectomy , a small part of the fallopian tube is removed or tied up through a small incision in abdomen or through vagina = ½ + ½

                                                                          OR

(a) Do all pollen grains remain viable for the same length of time ? Support your answer with two suitable examples.
(b) How are pollen grains stored in pollen banks ? State the purpose of storing pollen grains in these banks.
Ans. (a) No = 1
         Examples :
(i) Cereals / rice / wheat - pollen grains / loose viability with in thirty minutes of their release = ½
(ii) In some members of Rosaceae / leguminoseae / Solanacease maintain viability for months = ½
(b) Using cryopreservation techniques / in liquid nitrogen (-196° C) = ½
Maintaining viability / preserving threatened species / preserving commercially important
plants / to be used for crop breeding programmes = ½