Question

Which of these are closely related?

• A. Bats - Rats
• B. Whales - Seals
• C. Duckbilled platypus - Pangolin
• D. Scaly anteater - Spiny anteater

Answer 1

The correct option is B Whales - Seals

Rats belong to order Rodentia of class Mammalia and are characterized by presence of single pairs of growing incisors in both upper and lower jaw. Bats, the only true flying mammals, are classified under order Chiroptera of class Mammalia and are characterized by presence of modified forelimbs in form of webbed wings. This makes option A incorrect. Both whales and seals are aquatic mammals that have homologous modified forelimbs with basic pentadactyl pattern but adapted to aquatic life. Presence of homologous flippers confirms their common ancestry and close evolutionary relationship. Option B is correct. Duck billed platypus is an egg laying mammal (monotremes) that serves as connecting link between reptiles and mammals. On the other hand, Pangolin is true placental mammal (eutherian); option C is incorrect. Option D is incorrect as spiny anteater is most primitive living egg laying mammal while scaly anteater (pangolin) is eutherian. Correct answer is B.