Question

Which one of the following characteristics is not shared by birds and mammals?

• A. Breathing using lungs
• B. Viviparity
• C. Warm blooded nature
• D. Ossified endoskeleton

Answer 1

The Correct Option is B

Oviparous and Viviparous Reproduction 

In the animal kingdom, reproduction can generally be classified into two major types based on the mode of birth:

• Oviparous: Organisms that lay eggs, with development occurring outside the mother's body.
• Viviparous: Organisms that give birth to live young, with development occurring inside the mother's body.

Reproductive Modes in Different Groups:

• Birds: Birds are always oviparous. They lay eggs, and the development of the young happens outside the mother's body inside the egg.
• Prototherian Mammals: Prototherians, such as the platypus and echidna, are also oviparous, laying eggs, unlike most other mammals.
• Other Mammals: Most mammals, except for prototherians, are viviparous. They give birth to live young after internal development in the uterus, such as in humans, dogs, and cats.

Conclusion:

In summary, birds are always oviparous, while prototherian mammals are oviparous, and the rest of the mammals are viviparous, giving birth to live young.