What is common between parrot, platypus and kangaroo ?
(a) Oviparity
(b) Homoiothermy
(c) Toothless jaws
(d) Functional post - anal tail

Options

A. Ovoaparity
B. Homoiothermy
C. Toothless jaws
D. Functional post - anal tail

Answer

To determine what is common between a parrot, platypus, and kangaroo, we need to analyze each of the options provided:

1. **Oviparity**:
- Oviparity refers to the reproductive strategy where animals lay eggs.
- The parrot lays eggs (oviparous), and the platypus also lays eggs (it is one of the few egg-laying mammals). However, the kangaroo is a marsupial that gives birth to live young (viviparous).
- Therefore, this characteristic is not common to all three.

2. **Homoiothermy**:
- Homoiothermy, or endothermy, refers to the ability of an organism to maintain a constant body temperature regardless of the environment.
- Both the parrot (a bird) and the kangaroo (a mammal) are homoiothermic. The platypus, although a monotreme, is also capable of regulating its body temperature.
- Thus, this characteristic is common to all three organisms.

3. **Toothless jaws**:
- Parrots have beaks instead of teeth, and the platypus also lacks teeth, having flat grinding surfaces instead. However, kangaroos have teeth.
- Hence, this characteristic is not common to all three.

4. **Functional post-anal tail**:
- Parrots have tails, and kangaroos have tails that serve various functions. The platypus also has a tail, but it is not a post-anal tail in the same sense as in birds and marsupials.
- Therefore, this characteristic is not common to all three.

After analyzing all options, the only characteristic that is common among parrot, platypus, and kangaroo is:

**Answer: (b) Homoiothermy**

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