Classification of Animal Kingdom MCQs for NEET — Zoology Questions with Answers

The smallest level of organization in living organisms is the molecular level. This is where the basic building blocks of life, such as proteins, lipids, and nucleic acids, are found. These molecules form the basis for all higher levels of biological organization.

The kangaroo rat is well known for its ability to obtain water by oxidizing lipids in its diet. This metabolic water helps the animal survive in arid environments where free water is scarce.

Marine fish are adapted to live in saltwater environments, where they regulate their internal salt concentration to match the surrounding water. If a marine fish is placed in fresh water, it cannot adapt to the sudden change in salinity and will suffer from osmotic shock, leading to its death. Therefore, the correct answer is 'No, Because it can not adapt.'

Marine habitats have a high concentration of salts compared to the body fluids of marine organisms. This creates a hypertonic environment, where the concentration of solutes in the habitat fluid is higher than in the body fluid of the organisms. Therefore, marine organisms often have to regulate their internal osmotic balance to survive.

Collar cells, also known as choanocytes, are specialized cells found in sponges (Phylum Porifera). These cells have a flagellum surrounded by a collar of microvilli and are responsible for creating water currents and capturing food particles.

The canal system is a characteristic feature of sponges (Phylum Porifera). This system consists of a network of channels and chambers through which water circulates, allowing sponges to filter feed and exchange gases.

In Porifera, the skeleton is made up of both spicules and spongin. Spicules are small, spike-like structures made of calcium carbonate or silica, while spongin is a fibrous protein. Together, they provide structural support to the sponge body.

Physalia, commonly known as the Portuguese man o' war, is a marine hydrozoan. It is not a single animal but a colonial organism made up of specialized individual animals (zooids) working together.

To match the items correctly, we need to associate the organisms with their phyla. Spongilla is a freshwater sponge that belongs to Porifera. Adamsia, also known as sea anemone, belongs to Cnidaria. Liver fluke is a parasitic flatworm that belongs to Platyhelminthes. Nereis is a type of polychaete worm that belongs to Annelida. Thus, the correct matching is: p - (i), q - (iv), r - (ii), s - (iii).