Q.15. Which of the following is present in birds but absent in most mammals?
(1) Lungs
(2) Hairs
(3) Cloaca
(4) Red bone marrow

Dear Student,
 
Please find below the solution to the asked query:
The correct option is (3) Cloaca. Birds used to reproduce using their cloaca.
 
 
Hope this information will clear your doubts about the topic.
If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible.
 
Regards