An abnormal human baby with 'XXX' sex
chromosomes was born due to :

Which of the following are the important floral
rewards to the animal pollinators?

Match each disease with its correct type of vaccine:
(a) tuberculosis            (i) harmless virus
(b) whooping cough     (ii) inactivated toxin
(c) diphtheria              (iii) killed bacteria
(d) polio                     (iv) harmless bacteria

The following graph depicts changes in two
populations (A and B) of herbivores in a grassy field
A possible reason for these changes is that:

Which one of the following statements is wrong?

Secondary Succession takes place on/in: