Question

These are egg-laying mammals
A. Spiny anteater and duck-billed platypus
B. Spiny anteater and opossum
C. Spiny anteater and scaly anteater
D. Opossum and kangaroo

Answer 1

Mammals are warm blooded vertebrates which are one of the most highly evolved species on the surface of the earth. Few of the characteristics associated with mammals are- presence of body hair or fur, the jaw is hinged directly to the skull, presence of mammary glands and a complex brain.

Complete Answer:
- Reproduction is the process by which organisms produce offspring. The reproductive system of mammals is quite developed and involves the fusion of the male and female gate to produce young ones.
- The reproduction of mammals can be divided into three types-placental mammals, marsupials and monotremes.
- Placental mammals are the ones that are characterized by the presence of placenta. Placenta helps in the exchange of nutrients and wastes between the mother and the foetus. Few examples include humans, dogs , cats, elephants.
- For the case of marsupial reproduction organisms are born while still in their embryonic stage and reach the pouch on the surface of the mother’s body till it develops fully.
Examples include kangaroos, opossums, koalas, wombats.
- Monotremes are mammals that lay eggs instead of bearing the living young one. The eggs are retained within the mother for sometime and hatch within ten days of laying. Examples include duck-billed platypus, spiny anteaters.

So the correct answer is A) Spiny anteater and duck-billed platypus.

Note: Different mammals have different methods of reproduction. These methods have evolved over time and each method is best suited to the mammals possessing them.