Chapter 29.2, Problem 3MI

Solution

To state:

The definition of each term.

Introduction:

The birds included in the class Aves which belong to the phylum Chordata. Birds are warm-blooded animals whose forelimbs are modified into wings. their body is covered with feathers. Feathers may be contour or down feathers. The hind limbs of birds are adapted for perching, grasping, walking, hopping. They have a four-chambered heart and undergo pulmonary respiration.

The order and one member of the order for each distinguishing characteristic are given below in the table:

Term	Definition
Endotherm	The organism which generates its body heat internally by its metabolism.
Feather	A specialized outgrowth of the skin of birds which provides insulation and enables the birds to fly.
Contour feather	A type of feather that covers the body, wings and tail of a bird.
Preen gland	A gland located near the base of a bird’s tail which secretes oil for waterproofing feathers.
Down feather	It is a soft feather that is present beneath contour feathers.
Sternum	A long flat breastbone which located in the central part of the body of a bird.
Air sac	A saclike structure located at the anterior and posterior of a bird’s respiratory system.
Incubate	Maintenance of suitable conditions for hatching.