What is the main difference between monotremes and eutherians in terms of reproduction?

• A. Monotremes have a placenta, while eutherians do not.
• B. Monotremes have a higher metabolic rate than eutherians.
• C. Monotremes lay eggs, while eutherians give birth to live young.
• D. Monotremes are marsupials, while eutherians are not.

Answer: (C)

Verified step by step guidance

1. Understand the classification of mammals: Mammals are divided into three main groups based on their reproductive strategies: monotremes, marsupials, and eutherians (placental mammals).
2. Identify the characteristics of monotremes: Monotremes are unique among mammals because they lay eggs. They include species like the platypus and echidnas.
3. Identify the characteristics of eutherians: Eutherians, also known as placental mammals, give birth to live young. They have a complex placenta that nourishes the developing fetus during gestation.
4. Compare the reproductive strategies: The key difference between monotremes and eutherians is that monotremes lay eggs, while eutherians give birth to live young.
5. Clarify misconceptions: Monotremes are not marsupials, and they do not have a placenta like eutherians. Marsupials, another group of mammals, give birth to underdeveloped young that typically continue to develop in a pouch.