Biology Past Questions and Answers

The nitrogenous substance that is excreted by birds in order to conserve water is

In mammals, the exchange of nutrients and metabolic products occurs in the

In which of the following groups of vertebrates would the largest amount of yolk be found in the egg?

In snails, the hard calcareous shells are secreted by the

The structure that prevents food particle from escaping through the fish gills are called gill