Page 6 - SAAT BIOLOGY PART 2

SAAT BIOLOGY MR.MOHAMED ELGAYAR MRPROF.NET
▪ Birds

• Characteristics: its body is covered with feathers, light

weight bones, constant body temperature, heart made of four

chambers (two arteries that receive blocd, two ventricles that

pump blood), does not have teeth, does not have a bladder,

and contains air sacs that makes

oxygenated air rush through its

lungs.

Feathers: are extra parts that

grow from the skin of birds and made mainly of keratin.

▪ Types of feathers:

vaned feathers which cover the exterior of the body, and

down feathers which are underneath the vaned feathers. The

pennaceous feathers are vaned feathers. Also called contour

feathers, pennaceous feathers arise from tracts and cover the

entire body.

MRPROF.NET MR.MOHAMED ELGAYAR MRPROF.NET@GMAIL.COM