Question

According to Allen’s Rule, the mammals which live in colder climates have:
A. Shorter ears and longer limbs
B. Longer ears and shorter limbs
C. Longer ears and longer limbs
D. Shorter ears and shorter limbs

Answer 1

Hint: We all know that the animals and plants living in different environments develop different features according to their environment. This is known as adaptation. Allen’s Rule is a similar rule based on the adaptation of animals especially mammals living in the colder climate.

Complete answer:
To know the complete answer to the question, we must be well aware of the Allen’s Rule.
We all know that in colder climates, animals or rather mammals need features which would help them retain their body heat. They either have body hair or shorter limbs and shorter ears so that their body heat does not get dissipated. They have less surface area to volume ratio so that their body heat can be conserved.
Allen’s Rule was formulated by Joseph Allen who said that mammals from colder climates have shorter ears and shorter limbs so that they do not lose their heat.

Therefore, the correct answer to this question is Option D.

Note: The probable reasons for Allen’s Rule that various other scientists came up with were that in vertebrates the growth of the cartilage is somewhat dependent on the temperature. To prove this various experiments were performed on rats. These experiments proved that rats which were kept in colder climates had shorter limbs and tail as compared to rats which were kept in warmer temperatures.