Top 10 Must-Know Animal MCQs for NEET Biology

To score well in NEET, AIIMS, AIPMT, and JIPMER examinations, you need to be knowledgeable about the Animal Kingdom. The examiners love asking questions about the same animal repeatedly to test students’ knowledge about the circulatory system, physiological features, and taxonomy. So, if you are good at questions on high-yield animals, it will give you a great edge over others. For instance, you need to know about the unique water vascular system of starfish and the respiratory system of whales, frogs, and cockroaches to sail through these exams.

Here we come with the list of the top 10 animals that appear most often in exams, followed by some important solved multiple-choice questions (MCQs) to help you prepare for your biology exam by understanding what questions have appeared in the past.

1. Elephant

1. Elephant - Mammal: Taxonomical Classification (Class: Mammals) The elephant possesses all the standard features of the members of the class Mammalia. They have skin covered with hair, their teeth are of different types (heterodont), they have mammary glands for nourishing their young ones and also give birth to young ones (viviparous), so that they are referred to as Mammals. In competitive examinations like AIPMT and NEET, more questions are raised on their taxonomical classification based on some basic features of the vertebrates.

2. Elephant: Dentition with Heterodont: Having different types of teeth (incisors, canines, premolars, and molars) is referred to as possessing a heterodont dentition. Elephants, whose large tusks are modified upper incisors used in combination with their special molars, are an example of animals with heterodont dentition. By contrast, birds, like a pigeon, lack teeth entirely, and frogs and lizards, which possess homodont dentition, or uniform teeth, are examples of animals with homodont dentition.

3. Elephants: Reproduction and Viviparity: Unlike oviparous animals, viviparous mammals give birth to fully formed young ones. The elephant is a viviparous mammal that uses the placenta to nourish its foetus till it is born. In contrast, pigeons, which are aves, lizards, which are reptiles, and frogs, which are amphibians, are oviparous animals.

2. Whale

4. Whales are classified as aquatic mammals: The whale is classified within the class Mammalia because although it possesses a fish-like body adapted for swimming, it also has typical mammalian features such as using lungs to breathe atmospheric air, being warm-blooded (homoeothermic), viviparous, and having mammary glands to produce milk for its young ones.

5. Pulmonary Respiration in Whales: Although whales live in water, they are not fish because they lack gills and have lungs to breathe air. Their blowholes, located on the top of the head, allow them to breathe oxygen from the atmosphere surrounding their bodies every time they float up. Thus, whales are considered to have a specialized respiratory system that allows them to reach great depths and return to the surface to inhale oxygen through their blowholes.

6. Whale: Warm-Blooded Animal: The whale is a warm-blooded animal that lives in water and is capable of maintaining a constant body temperature regardless of the temperature of its surroundings. Warm-blooded animals have a thick layer of fat that insulates them from the water. Sharks, rohu (a fish), and octopus (a mollusc) are cold-blooded animals that cannot regulate their body temperatures and are therefore dependent on the temperatures of their environments.

3. Shark

7. Cartilaginous Endoskeleton (Class Chondrichthyes): Shark: Sharks belong to the class Chondrichthyes and thus possess an endoskeleton made up of cartilage, rather than true bones in them. Frogs (amphibians) and pigeons (birds) have a skeletal system that consists of bones that are ossified for the complex body plan of their terrestrial or aerial forms, respectively. Whereas Rohu is a bony fish (class Osteichthyes).

4. Fish

8. Fish: Gills for Branchial Respiration: Fish use their gills, which are specialized respiratory organs, for obtaining oxygen directly from the water. Water flows through the gills either through the mouth, over the gill filaments, which are highly vascularized, allowing gas exchange, and out of the gill openings. Unlike insects, which have tracheae or lungs, and fish, which have branchial breathing, water is the medium through which aquatic fish take in oxygen.

9. Fish have a single circulation and a two-chambered heart: Fish have a simple heart that has only two chambers: one ventricle and one atrium (auricle). They have a single circulatory system, and their heart pumps the blood that comes from the ventricles directly to the gills, to be oxygenated and then distributed to the rest of the body, going directly back to the atrium.

5. Starfish

10. The water vascular system of starfish (Phylum Echinodermata): One of the unique characteristics of echinoderms (including starfish) is the water vascular (ambulacral) system. The tube feet, or podia, which are used for movement and other purposes (feeding, adhesion, and gas exchange) are connected by a network of water-filled tubes. This system is absent in invertebrates such as snails, cockroaches, and earthworms.

11. Adult Starfish: Radial Symmetry: The body parts of the adult starfish (phylum Echinodermata) are arranged in a geometrical pattern around the central axis and radiate from it in multiples of five. This kind of symmetry is called pentamerous radial symmetry. However, the larvae of the starfish possess bilateral symmetry. Thus, the formation of the radial symmetry in the adult stage is an example of secondary radial symmetry. And this fact is often tested in medical exams such as AIPMT and NEET.

12. Starfish have a high level of regenerative abilities: Compared to higher vertebrates and arthropods, starfish demonstrate exceptional powers of epimorphic regeneration. Starfish can regenerate damaged tissues, and if an arm is cut off, then it can form a new starfish if the central part remains on the cut arm. In comparison, cockroaches, frogs, and lizards have a considerably more limited and tissue-specific ability to regenerate.

Birds

13. Pneumatic Bones for Volant Adaptation in Birds: Birds have hollow pneumatic bones, which are connected to the air sacs of the respiratory system and which serve primarily to reduce weight, enabling energy-efficient flight and easy take-off, with no loss of mechanical power or rigidity.

14. The Role of Air Sacs in Birds: Birds’ air sacs allow maintaining a high metabolic rate while providing oxygen to the tissues when they need it most: during intense physical activity. The air sacs not only reduce the bird’s body weight but also increase its buoyancy, thus improving thermal regulation and enabling the organism to fly at high altitudes.

15. Birds: Double circulation and a four-chambered heart: A heart with two atria and two ventricles makes up the completely divided four-chambered heart in birds. In comparison to the hearts of other animals, birds’ hearts carry oxygenated and deoxygenated blood independently and efficiently, enabling them to have a powerful double circulation that satisfies their voracious metabolism, endothermy, or warm-blooded nature, and overall high levels of activity and energy during flight.

6. Snakes

16. Taxonomy of the Snakes Essay (Article): Because they possess characteristics that are common to reptiles, such as pulmonary respiration, poikilothermy, and dry, cornified skin covered with epidermal scales or scutes, snakes are ingrouped into the Reptilia class. They are tetrapods that evolved a way to lay cleidoic (shelled) eggs on land, which allowed them to reproduce outside of water, having lost limbs in the process.

17. Snake: Poikilothermy (Cold-Blooded Nature): Being cold-blooded (poikilothermic) creatures, snakes are unable to regulate their body temperature due to the inability to control the production of heat by their bodies; instead, they have to rely on external factors to warm or cool their bodies. Hence, the most appropriate example of a snake’s reaction to the change in environmental temperature would be seeking shade when it is too hot. Meanwhile, warm-blooded (homoeothermic) animals such as whales, elephants, and pigeons are capable of withstanding drastic temperature changes due to their ability to control their body temperature.

7. Crocodile

18. The exception to the four-chambered heart is the crocodile: Crocodiles are an exception to the rule that most reptiles, such as lizards, snakes, and turtles, have a three-chambered heart with an incompletely formed septum between the ventricles. The crocodile has a four-chambered heart with two atria and two whole ventricles in order to prevent mixing of oxygenated and deoxygenated blood.

8.Frog

19. Taxonomic Classification of Frogs (Class Amphibia): The class Amphibia includes frogs because they can live both in water and on land, possess cold blood, have thin and smooth skin covered with glands that allow them to breathe, and have larvae that live in water and later metamorphose into adults.

20. Cutaneous Respiration in Frogs: One of the peculiarities of amphibians such as frogs that distinguishes them from other animals is cutaneous respiration, or gas exchange through the skin. In particular, during hibernation, aestivation, and underwater activity, frogs possess highly vascularized, thin, and moisture-permeable skin that allows them to dissolve oxygen from the air or water and transfer it to the blood.

21. Indirect Development and Metamorphosis in Frogs: The process of metamorphosis is the transformation from simple immature forms to more complex mature forms. Complete indirect development occurs in frogs. Under the influence of thyroxine, their development goes from an aquatic gill-bearing tailed stage (tadpole) to a lung- and skin-breathing, four-legged, air-breathing adult frog. The development of elephants, pigeons, and snakes is direct, with no larval stage.

9. Cockroach

22. Cockroach: Hemolymphatic Open Circulatory System: A thirteen-chambered tube heart pumps blood ( hemolymph ) into open body cavities where various organs are suspended (A cockroach’s heart is made up of a long muscular tube with 13 funnel-shaped chambers (3 in the thorax and 10 in the abdomen), whereas in humans (mammals), frogs (amphibians), and earthworms (annelids), the circulatory system comprises a closed network of blood vessels.

23. The tracheal system of cockroaches respiratory system: The tracheal system consists of numerous air tubes that penetrate the body wall and carry air to different parts of the body tissues. Unlike the fish, which uses the gills to absorb oxygen in the water, the frog, which uses the lungs and skin to breathe, and the earthworm, which uses the skin to respirate, the cockroach uses its tracheal system, which does not involve blood circulation. The air enters through small openings called spiracles; then it is carried into the tracheoles, where oxygen is transferred directly to the tissues.

24. Malpighian tubules help in the excretion of cockroaches: Malpighian tubules are thin, yellowish, filamentous structures that are found at the junction of the midgut and hindgut of cockroaches. The tubules reabsorb nitrogenous wastes and excess salts in the form of uric acid from the hemolymph before it is expelled out with the hindgut. This process prevents the loss of water in the cockroach body as the nitrogenous wastes are removed in a concentrated form, which is known as uricotelism.

10. Earthworm

25. Taxonomy of the Earthworms (Phylum Annelida): Due to the true coelom and the presence of metameric segmentation, or the division of the body into a series of ring-like segments from the inside out, earthworms are classified under the phylum Annelida. They move using hydrostatic pressure and chitinous setae, and lack jointed appendages typical of Arthropoda, a soft unsegmented body covered with a shell characteristic of Mollusca, and pseudocoeloms present in Nematoda.

26. The closed circulatory system of an earthworm: The circulatory system of the earthworms (phylum Annelida) is closed. It involves blood circulation through closed vessels, which includes the lateral pseudohearts and main arteries. This ensures effective transportation of carbon dioxide and oxygen at a high pressure. Contrary, the hemolymph of the cockroach (arthropods), Pila (molluscs), and starfish (echinoderms) is open or open-sinus, which directly surrounds the organs in the body cavity.

27. Earthworms are monoecious and hermaphroditic: A familiar example of an organism that exhibits hermaphroditism (or monoecism) is an earthworm that has both male and female sexual characteristics. Despite having both gonads, earthworms rarely fertilize themselves, and therefore, they need to copulate with each other to exchange sperm and form cocoons.

Also Watch the Video: Top 10 Animals Asked in NEET, AIIMS, AIPMT & JIPMER 🐾 | Must-Know Biology Questions

Conclusion

To score high in NEET, AIIMS, and JIPMER entrance exams, candidates must focus on studying the core concepts of these Animal Kingdom topics. By thoroughly understanding important adaptations, organ systems, and any exceptions to traditional classifications, students will be able to quickly recall the information needed to answer exam questions, prevent wrong assumptions from influencing their answers, and gain a deep understanding of biology fundamentals.