A Sea crab pulls a fresh hatching baby turtle towards the Sea water for its food as it is attached in the plastic thread of fishing nets at the Rushikulya river mouth beach at Podampeta in Ganjam district of Odisha. Baby Olive ridley turles returns back to the Bay of Bengal Sea after their hatching as it is the end process of the Olive ridley turtles mass nesting on the eastern coast of the Bay of Bengal Sea.
| Photo Credit: Biswaranjan Rout/The Hindu

Questions:

1. In this species of crabs, the males and the females have a major claw and a minor claw each. But among the males alone, the major claw is much larger than the minor one — a famous example of left-right asymmetry in biological systems. Name the species.

2. Fish belonging to the order Pleuronectiformes have some unusual features. One is that both X lie on the same side of Y, as a result of many species in this order swimming with one side of their bodies facing up. What are X and Y?

3. The left and the right sides of the human face can be said to have mirror symmetry. Often, however, there are minor deviations from perfect symmetry, as a result of minor genetic and environmental influences on the face as it developed biologically. What are such deviations called?

4. In most species of snails, as the gastropod develops from its larva, a process called _______ results in an asymmetric arrangement of its internal organs. Importantly, the snail’s anus is finally positioned above its head. Scientists aren’t yet sure why this process happens. Fill in the blank.

5. This species of plover bird is found only in New Zealand — and it’s the only species of bird in the world whose beak is bent sideways. Even more unusually, it’s always bent towards the right. Name the species.

Visual:

This genus of alga is also known as globe algae because its members form nearly perfectly spherical colonies of several thousand cells. Name the genus.

Answers:

1. Fiddler crab

2. X = eyes; Y = head

3. Fluctuating asymmetry

4. Torsion

5. Wrybill

Visual: Volvox