Assertion : The birds can maintain a constant body temperature.
Reason : Birds possess feathers covering their body

Options

A. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C. If the assertion is true but the reason is false
D. If both the assertion and reason are false

Answer

A

Explanation

Birds have a constant body temperature which commonly remains in between `104^@` to`112^@`, F even in subzero weather. Thus they are called homoiothermal. The feathers serve the most important function of retention of heat. Because the plumage forms an efficient, non-conduction covering with its innumerable dead air spaces, useful as insulation.