Free Kingdom Animalia MCQs with Answers

391. Dermal and denticle scales of fishes are called:

• A. Placoid scales
• B. Ganoid scales
• C. Ctenoid scales
• D. Cycloid scales

Explanation: The placoid scales of cartilaginous fishes are also called dermal denticles.

392. Among invertebrates, which possesses the greatest power of regeneration?

• A. Sponges
• B. Platyhelminthes
• C. Annelids
• D. Echinoderms

Explanation: Sponges can repair their body parts, even if a large part is lost. Sponges can regenerate the entire organism from the conglomeration of their cells. In Planaria, mainly the head or tail is regenerated in decapitated flatworms (some species). It is a fundamental concept in biology that the more complex an animal, the lesser is its power of regeneration. Therefore, echinoderms have the least power of regeneration and sponges have the greatest power of regeneration.

393. Excretory system, consisting of protonephridia tubes, are present in phylum:

• A. Porifera
• B. Annelida
• C. Platyhelminthes
• D. Cnidaria

Explanation: In Platyhelminthes, protonephridia are present. Protonephridia likely first arose as a way to cope with a hypotonic environment by removing excess water from the organism (osmoregulation).

394. Pinacocytes forms _.

• A. Pores
• B. Ostia
• C. Epidermis
• D. Spongocoel

Explanation: Options A: Pores are small openings in the epidermis that allow water to enter the sponge. Option B: Ostia are larger openings in the epidermis that also allow water to enter the sponge. Option C: Epidermis is the outer layer of cells in a sponge. It is made up of flat, plate-like cells called pinacocytes. Pinacocytes are responsible for protecting the sponge from the environment and allowing water to enter the sponge through pores. Option D: Spongocoel is the central cavity of the sponge. It is lined with choanocytes, which are cells that have flagella that create currents that draw water into the sponge.

395. Actinia is the biological name of:

• A. Sea Anemone
• B. Corals
• C. Obelia
• D. Jellyfish
• E. Frog

Explanation: Option A: The biological name of sea anemone is Actinia. They are a type of cnidarian, which are animals that have stinging cells. Sea anemones are found in shallow marine waters all over the world. They attach themselves to rocks or other hard surfaces and use their tentacles to capture prey. Option B: Corals are also cnidarians, but they are more closely related to jellyfish. Corals are colonial animals, which means that they form large colonies of individual polyps. The polyps are connected by a common tissue and share a digestive system. Corals are found in warm, shallow waters and build reefs. Option C: Obelia is a type of hydrozoan, which is another type of cnidarian. Hydrozoans are similar to sea anemones, but they are typically smaller and have a more delicate body structure. Obelia is found in freshwater and marine habitats. Option D: Jellyfish are also cnidarians, but they are more closely related to box jellyfish than to sea anemones. Jellyfish are free-swimming animals that have a bell-shaped body and trailing tentacles. They are found in all oceans of the world. Option E: Frogs are not cnidarians. They are amphibians, which means that they spend part of their life cycle in water and part on land. Frogs are found on all continents except Antarctica.

396. The simplest form in Kingdom Animalia belongs to:

• A. Eumetazoa
• B. Bilateria
• C. Protozoa
• D. Parazoa
• E. Protostomia

Explanation: Option A: Eumetazoa is a broad grouping of animals that have true tissues and organs. It includes all animals except sponges. Option B: Bilateria is a group of animals that have bilateral symmetry, meaning that they can be divided into two equal halves along a central axis. Most animals in the kingdom Animalia are bilaterians. Option C: Protozoa is a group of single-celled organisms that are not animals. They are classified in the kingdom Protista. Option D: The simplest form in Kingdom Animalia belongs to the group known as Parazoa. They are the simplest animals in the kingdom Animalia. Parazoans are multicellular animals that lack true tissues and organs. They include the phylum Porifera, which consists of sponges. Parazoans are considered the most primitive animals within the animal kingdom and have a simpler body organization compared to other animal groups like Eumetazoa, Bilateria, and Protostomia. Option E: Protostomia is a group of animals that have a blastopore that develops into the mouth. Most animals in the kingdom Animalia are protostomes.

397. Exoskeleton of cockroach is made up of:

• A. Cartilage
• B. Cuticle
• C. Chitin
• D. Amino acids

Explanation: The exoskeleton of a cockroach is made up of chitin. The skeleton of a cockroach is covered by thick hard chitinous cuticles secreted by the epidermis.

398. Which of the following phylum and its examples is not correct?

• A. Nematoda-Ascaris and Hookworm
• B. Annelid-Nereis and Leech
• C. Echinodermata-Sea star and Brittle star
• D. Platyhelminthes-Planaria and Liver fluke
• E. Cnidaria-Euplectella and Bath sponge

Explanation: Euplectell and bath sponge belong to the Phylum Porifera. Examples of phylum cnidaria include Hydra, Jellyfish, and Obelia.

399. The outer body wall of sponges is made up of which cells?

• A. Choanocytes
• B. Pinacocytes
• C. Mesenchymal cells
• D. Cnidocyte

Explanation: The outer body wall of sponges is made up of pinacocytes, which form a protective layer and cover the exterior surface of the sponge.

400. Open circulatory system is present in: (I) Arthropods. (II) Annelids. (III) Chordates. (IV) Molluscs

• A. III only
• B. III and II only
• C. I and IV only
• D. IV only
• E. I only

Explanation: The species in the phylum arthropoda have an open circulatory system. Open circulatory systems work by pumping the blood into a hemocoel. Molluscs have open circulatory systems like a snail, chiton, slug, etc, except for cephalopods which have closed circulatory systems. In Annelids the circulatory system is usually closed, i.e., confined within well-developed blood vessels. But in some polychaetes and leeches, the circulatory system is partly open, with blood and coelomic fluid mixing directly in the sinuses of the body cavity. Chordates also have a closed circulatory system, which can be either single or double looped. and most, but not all, chordates have a heart. Thus, the correct answer is option C.