Give reasons for the following:
Testes descend into the scrotum before birth.
Testes descend into the scrotum before birth to maintain the requires temperature for spermatogenesis and to keep sperms alive
Give reasons for the following:
Nitrogenous fertilisers are not applied in fields where leguminous crops grow.
Give reasons for the following:
At higher temperatures, green plants start evolving CO2 instead of O2.
State the best known contribution of:
(i) Alec Jeffery
(ii) P.K. Sethi
(iii) Hugo de Vries
(a) Name and define the three types of natural selection.
(b) State the following:
(i) Hardy Weinberg’s principle
(ii) Theory of recapitulation