How many of these is/are example(s) of homologous structures?
I. Vertebrate hearts
II. Potato and carrot
III. Potato and radish
IV. Vertebrate brains
V. Flippers of penguin and dolphin

The correct option is D Two
Homologous organs are those organs in different organisms which appear different but are similar in basic anatomical structure and have diverged from a common ancestor. Vertebrate hearts and vertebrate brains are examples of homologous structures.

The brains in different classes of vertebrates have evolved from the less developed brain of a common ancestor. Across different lineages, the presence of basic structures such as cerebrum, cerebellum, olfactory bulb and the spinal cord emerging from the brain have remained constant.


All vertebrates have chambered heart which consist of auricles and ventricles which originates from common ancester. The heart is two chambered in fishes, three chambered in amphibians and in some reptiles and four chambered in advanced reptiles, birds and mammals.


Analogous structures include those organs in different organisms that have different structures but apparently appear similar as they perform similar functions. Flippers of dolphins (mammals) and penguins (birds) have different internal structures (anatomy). They have different origins as well. However, both of them perform a common function, that is, swimming.


Potato is a modified stem whereas carrot and radish are modified roots. So these are analogous structures which have different structures and origin but the same function, that is food storage.