Free Kingdom Animalia MCQs with Answers

741. The body cells of sponges that secrete materials for the formation of skeletal spicules are:

• A. Porocytes
• B. Pinacocytes
• C. Choanocytes
• D. Amoebocytes

Explanation: The correct answer is amoebocytes. Amoebocytes are crucial in sponges for producing skeletal structures, as they secrete the materials needed to form spicules, which provide support and protection.Skeletal formation, which is specifically the role of amoebocytes.

742. In earthworm, excretion takes place through:

• A. Kidneys
• B. Protonephridia
• C. Metanephridia
• D. Protostomium

Explanation: Earthworms excrete waste through a system of structures called metanephridia. These are specialized tubules that filter waste from the body fluid and expel it through openings called nephridiopores.

743. The CORRECT sequence of stages (from I to V) in the life cycle of a cnidarian which shows alternation of generation is:

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: The correct order is polyp, medusa, egg, planula larva, polyp because the polyp produces medusae, the medusa releases eggs, the eggs develop into planula larvae, and the planula settles to form a new polyp.So option A is the correct option.The rest of the options are incorrect because they do not follow the proper sequence of the life cycle.

744. Closed circulatory system is present in animals belonging to phylum:

• A. Annelida
• B. Mollusca
• C. Nematoda
• D. Arthropoda

Explanation: The correct answer is Annelida. Animals in this phylum, such as earthworms, possess a closed circulatory system where blood circulates within vessels, allowing for more efficient transport of nutrients and gases.

745. Presence of shelled egg, dry skin and internal fertilization are evolutionary adaptations in:

• A. frog
• B. lizard
• C. kiwi
• D. kangaroo

Explanation: The presence of shelled eggs, dry skin, and internal fertilization are evolutionary adaptations primarily observed in amniotes, a group of vertebrates that includes reptiles, birds, and mammals. Lizard is most suitable answer

746. All of the following are characteristics of Chondrichthyes EXCEPT

• A. heterocercal tail
• B. 5-7 pairs of gills
• C. cartilaginous endoskeleton
• D. operculum over gills

Explanation: Chondrichthyes do not possess an operculum over their gills like bony fish (Osteichthyes) do. Instead, their gills are exposed directly to the water, often through multiple slits on the sides of their bodies. These gill slits are supported by cartilaginous structures rather than bony opercula.

747. Some animals like fiddler crab, busiest during the time of either dawn or dusk or both are called

• A. Diurnal animals
• B. Nocturnal animals
• C. Crepuscular animals
• D. Circadian animals

Explanation: In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine/vespertinal, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylight and of darkness, respectively.

748. Which type of behaviour helps animals with short life span to live successfully?

• A. Learning
• B. Innate
• C. Imprinting
• D. Altruism

Explanation: Innate behaviors are instinctual and are present in animals from birth. These behaviors are genetically programmed and can help animals with short life spans respond effectively to environmental stimuli without the need for learning. Examples include innate behaviors related to feeding, mating, and escaping from predators.

749. Choose the correct statement.

• A. All mammals are viviparous
• B. All cyclostomes do not possess jaws and paired fins
• C. All reptiles have a three chambered heart
• D. All pisces have gills covered by an operculum

Explanation: All cyclostomes lack true jaws and paired fins. Cyclostomes are jawless fish characterized by their round, sucker-like mouths for feeding and a single median fin for propulsion. Ornithorhynchus and Tachyglossus are oviparous mammals. Crocodile is a reptile which possesses four chambered heart. In cartilaginous fish (except Chimaera) gills are not covered by an operculum.

750. All of the following coelenterates show alternation of generation except:

• A. Hydra
• B. Obelia
• C. Aurelia
• D. All of these

Explanation: Metagenesis or alternation between polyp and medusa forms is a characteristic feature of phylum cnidaria. However, hydra exists only as a polyp and does not exhibit metagenesis.