Practice MCQs, Assertion–Reason, Match List and Fill in the Blanks from NCERT Class XI Animal Kingdom — answers & concise explanations.
Animal Kingdom - Class-XI: Practice ( MCQs, Assertion-Reason, Match List-I with List-II and Fill in the Blanks) for CBSE and NEET preparation 2026.
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Q361.
What is the function of the Osphradium in Molluscs?
[Animal-Kingdom] [class-xi]
Detect light
Check water quality
Grind food
Help in swimming
Correct Option: B [ Check water quality ]
Remark: The osphradium is a sensory organ found in the mantle cavity of molluscs. Its primary function is to test the chemical nature and quality of the incoming water.
Q362.
In Molluscs, where are the sensory tentacles located?
[Animal-Kingdom] [class-xi]
Visceral hump
Muscular foot
Anterior head region
Posterior tail
Correct Option: C [ Anterior head region ]
Remark: Sensory tentacles are distinct structures located on the anterior head region of Molluscs. They function as sensory organs to detect the environment.
Q363.
Hydra possesses a nerve net but lacks which structure?
[Animal-Kingdom] [class-xi]
Mouth
Brain
Tentacle
Body cavity
Correct Option: B [ Brain ]
Remark: While Hydra possesses a primitive nervous system consisting of a nerve net, it lacks a centralized brain or cephalization. This is typical of the simple organization in Cnidarians.
Q364.
The neurons found in Hydra are classified as?
[Animal-Kingdom] [class-xi]
Multipolar
Bipolar
Apolar
Unipolar
Correct Option: C [ Apolar ]
Remark: The neurons in Hydra are described as apolar because they lack a distinct differentiation into axons and dendrites. They form a diffuse network known as a nerve net.
Q365.
Nerve cells first appear in the evolutionary history of animals in which Phylum?
[Animal-Kingdom] [class-xi]
Porifera
Ctenophora
Coelenterata
Platyhelminthes
Correct Option: C [ Coelenterata ]
Remark: Coelenterata (Cnidaria) is the first Phylum in the Animal Kingdom to exhibit the presence of nerve cells and a nervous system, albeit a primitive nerve net.
Q366.
Do Poriferans (sponges) possess a nervous system?
[Animal-Kingdom] [class-xi]
Yes, well developed
Yes, primitive
No, absent
Only in larvae
Correct Option: C [ No, absent ]
Remark: Poriferans are at the cellular level of organization and lack tissues and organs, including nerve cells. Therefore, they do not possess a nervous system.
Q367.
Which cartilaginous fish is known for possessing electric organs?
[Animal-Kingdom] [class-xi]
Trygon
Scoliodon
Torpedo
Pristis
Correct Option: C [ Torpedo ]
Remark: Torpedo is a genus of cartilaginous fish (Chondrichthyes) that possesses specialized electric organs capable of generating strong electric shocks for defense and predation.
Q368.
What is the common name for the fish Torpedo?
[Animal-Kingdom] [class-xi]
Sting ray
Electric ray
Dog fish
Saw fish
Correct Option: B [ Electric ray ]
Remark: Torpedo is commonly referred to as the Electric Ray due to its ability to produce electric discharges. This distinguishes it from the Sting Ray.
Q369.
What is the common name for the fish Trygon?
[Animal-Kingdom] [class-xi]
Electric ray
Sting ray
Flying fish
Angel fish
Correct Option: B [ Sting ray ]
Remark: Trygon is commonly known as the Sting Ray. It possesses a venomous sting or spine on its tail which is used for defense.
Q370.
The Sting Ray (Trygon) uses its sting primarily to?
[Animal-Kingdom] [class-xi]
Generate electricity
Secrete poison
Produce light
Filter food
Correct Option: B [ Secrete poison ]
Remark: The sting of Trygon is associated with poison glands. It secretes poison to inflict painful wounds on potential predators as a defense mechanism.
