Question

Which of the following is an example of flightless birds (Ratitae)?
A.Struthio
B.Kiwi
C.Rhea
D.All of the above

Answer 1

Hint: All Birds are classified under class Aves under the superclass Tetrapoda. Ratitae is a group of flightless birds. The forelimbs of birds are modified into wings. They have bony endoskeleton with bones filled with air (pneumatic bones) to reduce their weight, so they can fly easily. The jaws are modified into beaks. Their feathers help in preventing heat loss and also reduce friction while flying.

Complete answer:
 Flightless birds come under the class Aves. Flightless birds refer to the birds which do not fly and are on the land itself.
Struthio: Ostrich is a species of largest flightless birds. Ostrich is under the genus Struthio. The only living members of the genus Struthio are ostriches. So, Struthio is among one of the genera of flightless birds.
Kiwi: Kiwi is the smallest living flightless ratite. Apteryx is the species of birds that fall under the genera of Kiwi. So, kiwi is one of the flightless birds genera.
Rhea: Rhea is a genus of flightless birds. The members of this genera resemble ostrich as they have long necks and long legs.

Hence the correct answer is option (D)

Note: Ostriches lays the largest egg of all birds. Ostrich eggs are the largest single-cell living being. The eggs of the ostrich are very hard as compared to eggs of other birds.