Taxonomy (Biology) Part-II

Thousands of lac insects colonize the branches of the host trees and secrete the resinous pigment. It is used in the manufacture of varnishes, sealing wax, shellac etc.

The most valuable pearls occur spontaneously in the wild (natural pearls which are rare), while cultured or farmed pearls are obtained from bivalve mollusks, such as pearl oysters (Pinctada) and freshwater mussels.

Earthworms build enormous haemoglobin complexes to carry their oxygen. These complexes are termed as erythrocruorin. It is composed of 144 separate globin chains, each with its own heme group to carry oxygen.

These globin chains come in four similar types (36 copies of each) similar to the slightly different alpha and beta chains found in human haemoglobin.

Then, 36 linker protein chains stitch all the globin chains together into one big complex. In earthworms, gases are exchanged through the moist skin and capillaries.

Earthworms are one of the few organisms that have haemoglobin without any red blood cells. Its affinity for oxygen is weaker than that of most haemoglobins. The enormous macromolecule, erythrocruorin, is typically found free floating in the plasma.

Dracunculus medinensis or guinea worm is a nematode that causes dracunculiasis, also known as guinea worm disease. The disease is caused by the female which is up to 800 mm in length and among the longest nematodes infecting humans.

A detritivore is an organism that eats dead or decaying plants and animals as food. Detritivore is a combination of the word detritus and the suffix -vore.

In other words, detritivores are heterotrophs that obtain nutrients by consuming detritus. By doing so, all these detritivores contribute to decomposition and the nutrient cycles. Detritivores are usually arthropods and help in the process of remineralization.

Typical detritivorous animals include millipedes, springtails, woodlice, dung flies, slugs, many terrestrial worms (e.g. earthworm), sea stars, sea cucumbers, fiddler crabs etc. Seahorses and jellyfish are not detritivores as they are secondary consumers. Hence, option (c) is the correct answer.

Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure.

Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers. They are also important in bioconcentration and, as a result, as indicator organisms.

Some animals that use this method of feeding are clams, oysters, krill, sponges, baleen whales, and many fish (including some sharks). Some birds, such as flamingos and certain species of duck, are also filter feeders.

Oysters like other shellfish have unique filter-feeding ability, in the sense it takes in water through its gills, which then filters it for nutrients like suspended fragments of plankton, while automatically draining out the rest of the water.

It is diurnal, meaning it is active exclusively in daylight hours. They sleep at night in trees (typically, high in the canopy of rainforest). Hence, 1 is incorrect. The Malabar large-spotted civet (Viverra civettina), also known as the Malabar civet, is a viverrid endemic to the Western Ghats of India.

The Malabar civet is considered nocturnal and so elusive that little is known about its biology and ecology apart from habitat use. Hence, 2 is correct.

The sambar (Rusa unicolor) is a large deer native to the Indian subcontinent, South China and Southeast Asia. Sambars are nocturnal (active during the night) and crepuscular (active at dawn and dusk) animals. Hence, 3 is correct.