Question

Match the following mammals with their correct category and geographical distribution.

Column - I	Column - II
(P) Kangaroo	(1) Monotreme found in Australia
(Q) Platypus	(2) Marsupial found mainly in Australia
(R) Whale	(3) Placental mammal
(S) Echidna	(4) Egg laying mammal

Choose the correct option.

• A. \(P \rightarrow 2,\ Q \rightarrow 1,\ R \rightarrow 3,\ S \rightarrow 4\)
• B. \(P \rightarrow 1,\ Q \rightarrow 2,\ R \rightarrow 3,\ S \rightarrow 4\)
• C. \(P \rightarrow 2,\ Q \rightarrow 4,\ R \rightarrow 1,\ S \rightarrow 3\)
• D. \(P \rightarrow 3,\ Q \rightarrow 1,\ R \rightarrow 2,\ S \rightarrow 4\)

Hint:

Monotremes are the only egg-laying mammals. Examples:
• Platypus
• Echidna Marsupials possess a pouch called marsupium.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Mammals are broadly divided into three subclasses based on their mode of reproduction and development:
1. Prototheria (Monotremes): These are the most primitive mammals that lay eggs instead of giving birth to live young. Example: Platypus, Echidna.
2. Metatheria (Marsupials): These mammals give birth to very immature young that complete their development in a maternal pouch (marsupium). Example: Kangaroo.
3. Eutheria (Placental Mammals): These mammals nourish their developing young through a complex placenta and give birth to well-developed offspring. Example: Whale, Humans.
Step 2: Detailed Explanation:
Let us evaluate the specific matches:
- (P) Kangaroo: Kangaroos are quintessential marsupials. Due to long-term geographical isolation, Australia became a sanctuary for marsupials, where they radiated into various ecological niches. Therefore, P matches with (2) Marsupial found mainly in Australia.
- (Q) Platypus: The Duck-billed Platypus is a unique mammal that exhibits reptilian features like laying eggs. It is a monotreme endemic to Australia. Therefore, Q matches with (1) Monotreme found in Australia.
- (R) Whale: Despite being aquatic, whales are mammals. They are Eutherians (placental mammals), as they possess a placenta and give birth to live calves. Therefore, R matches with (3) Placental mammal.
- (S) Echidna: Also known as the spiny anteater, the Echidna is one of the very few surviving monotremes. Its primary characteristic in this context is that it is an egg-laying mammal. Therefore, S matches with (4) Egg laying mammal.
Aligning these: P-2, Q-1, R-3, S-4. This corresponds perfectly to option (A).
Step 3: Final Answer:
Matching the animals to their reproductive groups reveals that Kangaroo is a marsupial, Platypus is an Australian monotreme, Whale is placental, and Echidna is an egg-layer.
Final Answer: (A)