Chapter 31, Problem 1STP

Summary Introduction

Introduction:

Birds use their feathers to assist in flight. When a bird flaps down its wings in flight, the feathers shift together. Then, as the bird lifts its wings, the feathers move apart to allow the air to pass through. The movement of the feathers helps in the climb.

Answer to Problem 1STP

Correct answer:

The correct answer is option (a) insulation.

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) Insulation. A lot of feathers are soft, fluffy type; the down feathers objective is to insulate the birds from cold. Birds can survive in sub-zero conditions by fluffing their feathers and forming layers of air and feathers. Hence, option (a) is correct.

Explanation for incorrect answer:

Option (b) Nesting. Feathers do not help in nesting. Most of the bird nests reside right in the center, with the majority constructing cup-shaped nests using a mixture of mud, twigs and leaves and feathers. Some birds, such as flamingos and swifts, use saliva to help keep their nest intact.

Option (c) Conserving water. Feathers do not help in conserving water. Birds store digestive waste, uric acid and gametes in a chamber called a cloaca. Due to the presence of uric acid in the cloaca, birds are able to conserve water.

Option (d) Swimming. Most of the birds that swim in freshwater propel themselves with feet. Like Penguins, they have solid bones and they float at low heights.

Conclusion

Insulation is the function of feathers. Hence, the correct answer is Option (a) insulation.