Question

Which one has a raft-like keel, a preen gland and a penis?
A) Dromaius
B) Passer
C) Struthio
D) Tinamus

Answer 1

Hint:The keel bone provides the main attachment to the light muscles .Sternum is raft like & without keel. Furcula, syrinx, preen glands etc. are absent. Male birds have penis.

Complete answer
Let’s discuss the given option and find the answer:
>Dromaius cannot fly. Their wings are only eight inches (20 cm) long and they lack flight feathers, the breastbone, or keel, and the muscles needed for flight. However they have very strong legs for running and can reach speeds of 30-35 mph for short distances. They can walk considerable distances at a steady rate of four and a half mph.
>Passer is a true sparrow also known as genius sparrow. The genus includes the house sparrow and the Eurasian tree sparrow, two of the most common birds in the world.
>Struthio may be a genus of bird within the Struthioniformes , whose members are the ostriches. There are two living species, the common ostrich and therefore the Somali ostrich.
>Tinamous have all the three mentioned features, that is, they need a raft-like keel, they need a uropygial gland and that they also possess a penis, which rarely some birds do.

Hence, the correct answer is option d: Tinamous.

Note: Tinamous belongs to the species of Ostriches though ostriches are completely flightless and Tinamous can fly fast.