Question

Hair occur in all mammals except those of

• A. rodentia
• B. chiroptera
• C. primata
• D. cetacea.

Answer 1

The Correct Option is D

Mammals are a diverse group of animals that primarily possess hair at some stage in their life cycle. However, there are exceptions within the animal kingdom where this characteristic is minimized or absent. The question asks which group of mammals do not possess hair, and the options provided are:

• Rodentia
• Chiroptera
• Primata
• Cetacea

Let's analyze each option:

1. Rodentia: This is an order that includes rodents like mice, rats, and squirrels, which typically have fur or hair.
2. Chiroptera: This order refers to bats, which have hair on their bodies covering their wings.
3. Primata: This order includes primates, such as monkeys, apes, and humans, all of which possess body hair to some degree.
4. Cetacea: This order includes marine mammals such as whales, dolphins, and porpoises. Members of Cetacea are adapted to aquatic life and generally lack hair, having smooth skin to reduce drag while swimming.

Based on this analysis, the correct answer is cetacea as they mostly do not have hair, unlike other mammals. The absence of hair is an adaptation to their aquatic lifestyle, helping streamline their bodies for efficient movement through water.

Hence, the correct choice is cetacea as the group of mammals generally lacking hair.