Among the following animals, which one lays eggs and does not give birth to live young ones directly, thus representing an egg laying mammal known as a monotreme?

Introduction / Context:
Most mammals are viviparous, meaning they give birth to live young. However, a very small and special group of mammals called monotremes are oviparous, which means they lay eggs. Competitive examinations frequently include a question asking candidates to recognize these rare egg laying mammals. This question checks whether the learner can identify which listed animal lays eggs rather than producing live young ones directly.

Given Data / Assumptions:

• We are comparing four mammals: Echidna, Kangaroo, Porcupine, and Whale, with an additional decoy option.
• The question asks for an animal that lays eggs.
• We assume standard zoological classification of mammals into monotremes, marsupials, and placental mammals.
• We also assume that only one option refers to a monotreme.

Concept / Approach:
Monotremes are primitive egg laying mammals. The best known monotremes are the platypus and the echidnas (spiny anteaters), which are native to Australia and nearby regions. They lay eggs but also produce milk to feed their young, so they combine reptile like egg laying with mammalian features. In contrast, kangaroos are marsupials that give birth to live but immature young, porcupines are placental mammals, and whales are fully marine placental mammals. Therefore, the correct approach is to identify which among the options is a monotreme.

Step-by-Step Solution:
Step 1: Recall the group of mammals that lay eggs, known as monotremes. Step 2: Remember the main examples of monotremes, which are the platypus and the echidnas. Step 3: Examine the options and identify Echidna as one of the known monotreme mammals. Step 4: Recognize that kangaroos are marsupials with a pouch, porcupines are rodents, and whales are large marine mammals that give birth to live young. Step 5: Conclude that the only egg laying mammal listed is Echidna.

Verification / Alternative check:
As an additional check, we can recall that textbooks and reference materials often state that only two types of mammals lay eggs, namely the platypus and echidnas, which live in Australia and surrounding regions. None of the other animals listed in the options fall into this category. Kangaroos are iconic live bearing marsupials, whales give birth to calves in the ocean, and porcupines give birth to live young. This confirms that Echidna is the correct answer.

Why Other Options Are Wrong:
Option B: Kangaroo is a marsupial that gives birth to live but underdeveloped young that continue developing in the pouch, so it is not egg laying. Option C: Porcupine is a rodent and a placental mammal that gives birth to live young. Option D: Whale is a marine mammal that gives birth to live calves and does not lay eggs. Option E: Camel is a placental mammal adapted to desert life and gives birth to live young.

Common Pitfalls:
Some learners mistakenly think that all animals that look primitive or reptile like must lay eggs. Others may confuse marsupials such as kangaroos with egg laying mammals because both are unusual compared to typical placental mammals. Another error is to assume that aquatic animals like whales behave like fish and might lay eggs, but whales are fully mammalian and are viviparous. Remembering the word monotreme and its two classic examples, the platypus and echidna, helps avoid these misconceptions in exam settings.

Final Answer:
The mammal among the options that lays eggs rather than giving birth to live young directly is the Echidna.