Question

Ear pinnae are present in
A) Amphibia
B) Reptilia
C) Aves
D) Mammalia

Answer 1

Hint: It is the class of Vertebrate animals. They have glands in which females produce milk for feeding their young. They are intelligent, with some possessing large brains.

Complete Answer:
- Ear pinnae is the visible part outside the head also known as auricle.
- Pinnae is first noticeable around the 6th week of gestation in the human foetus, it develops in auricular hillocks. Pinnae basically helps in collecting sound. It collects sound as a funnel, amplifying the sound and directing it to the auditory canal.
- These visible pinnae are a trait in mammals.
- Mammals have external ears or pinnae but one of the mammals has no pinna which is Echidna. Echidna is also known as spiny anteater.

Thus, the correct answer is option D i.e., Mammalia.

Additional information:
- Amphibia is a class containing amphibians. They are small vertebrates’ animals. They inhabit a wide variety of habitats; they typically start out as larvae living in water. The young generally undergo metamorphosis.
Example: Frog, Salamander, caecilians etc.
- Reptilia is a class of tetrapod animals called reptiles. They have 4 limbs or like snakes.
- Birds come under the class of Aves which includes warm-blooded vertebrates. They have a four-chambered heart, high metabolic rate, and lay hard-shelled eggs.

Note: Mammals are the intelligent class of vertebrate animals which possess large brains. In mammals, ear pinnae are present which is where the visible part lies outside the head. It is made up of rigid cartilage covered by the help of the skin of the mammals. Ear of pinnae are absent in echidna.