Question

A pigeon with no down features will not be able to
A) Fly for long distance
B) Protect against ectoparasites
C) Exhibit secondary sexual dimorphism
D) Keep the body warm

Answer 1

Hint:Birds are characterized as egg laying animals. They have wings or feathers which help them to fly. Birds fall under the kingdom Animalia Phylum Chordata and class Aves. The characteristic feature of a user are warm blooded vertebrates. They are having feathers on their body.

Complete answer:
Aves are egg laying animals and their body is covered with features. They produce offspring by laying eggs which are fertilized by sexual reproduction. They lay eggs which are covered with a hard shell. They have high metabolic rates. The light skeleton enables them to fly. They also have tooth less beaked jaws. The digestive and respiratory system of the birds are adapted in accordance with flight. The heart is four chambered. Power genus words for example peacocks have bright coloured feathers which they used for flying small distances. But as they lay eggs to produce offspring, it comes under the category of birds.
The down feathers of the birds are a layer of fine feathers which are found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialised type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding, pillows and sleeping bags. The Loose structure of down feathers traps air, which helps to insulate the bird against heat loss. Thus if down feathers are absent, pigeons will not be able to keep the body warm.

Thus, the correct answer is option ‘D’ Keep the body warm.

Note:Some birds are flightless, for example, penguins. They have adapted as per the environmental conditions. Some birds are adapted for swimming, for example sea birds and water Birds. Testudo genus for example, tortoise does not come under Aves. rather it comes under the class reptilia.