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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Q11.
What is the undifferentiated layer present between the ectoderm and endoderm in diploblastic animals called?
[Animal-Kingdom] [class-xi]
Mesoderm
Mesoglea
Coelom
Endoskeleton
Correct Option: B [ Mesoglea ]
Remark: Explanation: Mesoglea is an undifferentiated layer present between the ectoderm and the endoderm in diploblastic animals like coelenterates.
Q12.
The body cavity which is lined by mesoderm is called a:
[Animal-Kingdom] [class-xi]
Pseudocoelom
Haemocoel
Coelom
Spongocoel
Correct Option: C [ Coelom ]
Remark: Explanation: The coelom is the body cavity that is lined by the mesoderm germ layer.
Q13.
Which of the following is an example of a coelomate animal group?
[Animal-Kingdom] [class-xi]
Platyhelminthes
Aschelminthes
Coelenterates
Annelids
Correct Option: D [ Annelids ]
Remark: Explanation: Animals possessing a true coelom are called coelomates. Examples include annelids, molluscs, arthropods, echinoderms, hemichordates, and chordates.
Q14.
Aschelminthes are characterized by the presence of a body cavity that is not lined by mesoderm, known as a:
[Animal-Kingdom] [class-xi]
Coelom
Pseudocoelom
Acoelom
Gastro-vascular cavity
Correct Option: B [ Pseudocoelom ]
Remark: Explanation: In pseudocoelomates like aschelminthes, the body cavity is not lined by mesoderm; instead, the mesoderm is present as scattered pouches. This type of cavity is called a pseudocoelom.
Q15.
The phenomenon where the body is externally and internally divided into segments with a serial repetition of some organs is known as:
[Animal-Kingdom] [class-xi]
Metagenesis
Metamerism
Bioluminescence
Regeneration
Correct Option: B [ Metamerism ]
Remark: Explanation: The pattern of external and internal division of the body into segments with serial repetition of organs is called metameric segmentation, and the phenomenon is known as metamerism.
Q16.
What is the rod-like structure derived from mesoderm, formed on the dorsal side during embryonic development in some animals?
[Animal-Kingdom] [class-xi]
Nerve cord
Vertebral column
Notochord
Stomochord
Correct Option: C [ Notochord ]
Remark: Explanation: The notochord is a mesodermally derived rod-like structure formed on the dorsal side during the embryonic development of some animals.
Q17.
Members of Phylum Porifera are commonly known as:
[Animal-Kingdom] [class-xi]
Flatworms
Roundworms
Sponges
Sea walnuts
Correct Option: C [ Sponges ]
Remark: Explanation: Members of the Phylum Porifera are commonly known as sponges.
Q18.
The water transport or canal system in sponges is helpful for all the following functions EXCEPT:
[Animal-Kingdom] [class-xi]
Food gathering
Respiratory exchange
Removal of waste
Anchorage
Correct Option: D [ Anchorage ]
Remark: Explanation: The water transport system in sponges is helpful in food gathering, respiratory exchange, and removal of waste. Anchorage is a function of cnidoblasts in cnidarians.
Q19.
The central cavity in sponges, lined by choanocytes or collar cells, is called the:
[Animal-Kingdom] [class-xi]
Osculum
Ostia
Spongocoel
Coelom
Correct Option: C [ Spongocoel ]
Remark: Explanation: Water enters the sponge through pores (ostia) into a central cavity called the spongocoel, and exits through the osculum.
Q20.
The body of a sponge is supported by a skeleton made up of:
[Animal-Kingdom] [class-xi]
Chitin
Calcium carbonate
Spicules or spongin fibres
Cartilage
Correct Option: C [ Spicules or spongin fibres ]
Remark: Explanation: The body of a sponge is supported by a skeleton made of structures called spicules or spongin fibres.
