Give reasons for the following.
a. Frog tadpole excretes ammonia, adult frog excreles urea.
b. The chemical composition of DNA in almost all animals is similar.
c. For energy production all animals depend upon glycolysis and Kreb’s cycle
d. Connecting links play an important role in understanding the concept of organic evolution.
e. Change in germ cells is heritable.
f. Genetic drift is also known as bottle neck phenomenon.

Explanation

a. Excretion of ammonia needs more water. Urea needs only a little water for excretion.
b. Supposed to have common ancestor.
c. Common ancestry.
d. These animals have the characters of both aves and reptiles.
e. The information in the germ cells are only transferred to the next generation whereas in the somatic cells it is not.
f. Reduction in gene frequencies.