CBSE Questions for Class 11 Medical Biology Animal Kingdom Quiz 11 - MCQExams.com

• Caste, in biology, a subset of individuals within a colony(society) of social animals are specialized in the function it performs and distinguished by anatomical or morphological differences from other subsets.
• The Sand puppy is also known as Nakes Mole Rat.
• It's a burrowing rodent native to East Africa. It belongs to the genus Heterocephalus and family Heterocephalidae.
  
• Nakes Mole Rat is a  mammal with social life having different castes.
• So, the correct answer is 'Nakes Mole Rat'.

• Enucleated RBCs (RBCs without a nucleus) are present In all mammals. Though the RBCs may differ in shape, all of them are enucleated. The RBCs in birds, reptiles etc. are nucleated. 
• Muscular diaphragm and hairy skin are exclusive characteristics of Mammalians.
• Mammals are warm-blooded animals halving fully developed four-chambered hearts and are highly evolved organisms.

A. Correct option is- C
B. Explanation for the correct option

• Whales are not fish but mammals. They are the largest aquatic mammals.
• All insects have three pairs of legs. It is a characteristic feature of all arthropods.
• All mammals have mammary glands and hairs may be absent in some.
• Flame cells are special excretory cells present in Platyhelminthes having kidney-like functions

A. Correct option-D
 B. Explanation for the correct option

• The characteristic feature of mammals is mammary glands.
• These glands are involved in the production and secretion of milk that nourishes the young one.
• Parrot belongs to Aves, Earthworm is Annelida and Crocodile belongs to Reptilia. Hence they do not bear mammary glands.
• Rabbit belongs to class Mammalia and shows the presence of mammary glands. 

• $$\textit{Platypus}$$ is a connecting link between reptiles and mammals.
• It shows mammalian characters like mammary glands, hair, diaphragm, single aortic arch etc. 
• It also shows reptilian characters in having a large coracoid in the pectoral girdle and in laying eggs with yolk and shell.

So, the correct answer is option A. 

• The presence of a diaphragm is a peculiar feature of the mammalian group.
• Four-chambered hearts can be found in birds too.
• Mammals and birds are warm-blooded animals due to their ability to maintain their body temperature. 
• Rib cages are found in a lot of animals other than mammals like birds, reptiles, etc.

• In reptiles and amphibians both the arches are present (left and right).
• Birds have only right arc present in their adult form.
• Mammals have only the left arch present in their adult form.
• The systematic arch in the adult organisms transports blood to all the body parts except the head.
• So the correct answer is option A- 'Mammals'. 

All the mammals have different types of teeth (heterodont) for e.g., incisors, canines, premolars and molars. Other characters which define mammals are mammary glands, skin with hairs, external and middle ears, two pairs of limbs and placenta. So, the correct answer is option A.