Question

Which one of the following is not a mammalian character?
A. Enucleated RBC
B. Three chambered heart
C. Muscular diaphragm
D. Hairy skin

Answer 1

Hint: Mammals are recognized by their few unique characteristic features which generally involve giving birth to their young ones, mammary glands, placenta, internal fertilization, four chambered heart with muscular diaphragm, and skin with hair on it. These are few main characteristics of mammals for which they are recognized.

Complete answer:
Mammals are the group of vertebrates which possess some special characteristic features which makes them different from amphibians and reptiles. They come under the class of Mammalia and have mammary glands which are used to feed their young ones. Reptiles and amphibians have three chambered hearts whereas mammals are characterized by four chambered hearts. Approximately 6400 species of mammals have been described. Most mammals are intelligent as they possess large brains including humans, apes, monkeys, they can communicate through vocal cords they are provided with which makes different sounds in different mammals. Mammals are mostly warm blooded with enucleated RBCs and three middle ear bones, they have a neocortex region in their brain which is specialized in hearing and seeing the objects. Mammals do have teeth which help them to chew their food and to speak. Hence we can easily conclude that mammals do have enucleated RBCs, hairy skin and muscular diaphragm but they do not possess three chambered hearts as is found in reptiles and amphibians.

So, the correct answer is option B.

Note: The mammal has been kept by the scientist named ‘Carl Linnaeus’ from the scientific name ‘Mammalia’ in 1758. Mammals are found in every area, every continent and even ocean, they are adapted to the region in which they are born and living. Their size ranges from as small as bumblebee to as large as apes.