Animal Kingdom — Class 11 MCQs with Answers

Animal Kingdom — important questions & MCQs with answers (Class 11 Biology)

6 solved questions from this chapter's difficulty levels, each with its answer and explanation. Tap an option to check yourself.

0 of 6 answered

1. Q1 of 6Easy

   Sponges belong to phylum:

   AChordataBCnidariaCMolluscaDPorifera
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   Answer: Porifera

   Explanation: Sponges are Porifera: their pore-riddled body and choanocyte-lined canal system give a purely cellular level of organisation, unlike Cnidaria's tissue-level body built around stinging cnidoblasts.

2. Q2 of 6Easy

   Basis of classification of animal kingdom does NOT include:

   ASymmetryBGeographical distributionCCoelomDNotochord
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   Answer: Geographical distribution

   Explanation: Animal classification rests on body-plan characters -- symmetry, level of organisation, coelom, segmentation, notochord -- because these reflect evolutionary relationships; where a species lives is ecology, not a taxonomic criterion.

3. Q3 of 6Medium

   Coelom is a:

   ASensory cellBBrain partCExcretory organDBody cavity lined with mesoderm
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   Answer: Body cavity lined with mesoderm

   Explanation: A true coelom is a body cavity completely lined by mesoderm on all sides, marking coelomates off from pseudocoelomates (mesoderm lines only the outside) and acoelomates (no cavity) -- not a cell, organ or nerve structure.

4. Q4 of 6Medium

   Water canal system is characteristic of:

   AEchinodermataBCnidariaCCtenophoraDPorifera
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   Answer: Porifera

   Explanation: The water canal system, with choanocyte-lined canals for feeding and gas exchange, is unique to Porifera -- sponges have no gut or organs, so this canal network does the work other phyla assign to a digestive system.

5. Q5 of 6Hard

   Assertion: Aschelminthes are pseudocoelomates. Reason: Their coelom is not lined by mesoderm.

   AA true, R falseBBoth true; R does not explain ACBoth A and R true; R explains ADA false, R true
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   Answer: Both A and R true; R explains A

   Explanation: Aschelminthes are pseudocoelomates precisely because their body cavity, though present, is not lined by mesoderm on the outer side -- the reasoning behind the assertion is exactly why the classification holds, not a coincidence.

6. Q6 of 6Hard

   Unique mammalian feature is:

   AHair and mammary glandsBFeathersCScalesDPneumatic bones
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   Answer: Hair and mammary glands

   Explanation: Hair and mammary glands -- fur for insulation and milk-secreting glands for nursing young -- are the two features unique to Mammalia among vertebrates, unlike feathers (Aves) or scales (Reptilia).

Animal Kingdom notes: key concepts (Class 11 Biology)

Despite huge diversity, animals are classified on a few fundamental features — grade of body organisation, symmetry, germ layers, presence of a coelom, segmentation and the notochord. Applying this checklist sorts the kingdom from sponges through the invertebrate phyla to the chordates and their vertebrate classes.

Levels of organisation

Cellular (Porifera), tissue (Cnidaria), organ (Platyhelminthes) and organ-system (higher phyla) grades mark increasing division of labour in the body.

Symmetry

Animals are asymmetrical (sponges), radial (cnidarians, adult echinoderms) or bilateral (most others); bilateral forms have a distinct head end.

Germ layers

Diploblastic animals (Cnidaria) have ectoderm and endoderm with mesoglea between; triploblastic animals add a true middle layer, the mesoderm.

Coelom

A body cavity lined by mesoderm. Coelomates (annelids onward) differ from pseudocoelomates (Aschelminthes) and acoelomates (flatworms).

Segmentation & notochord

The body may be metamerically segmented, as in Annelida. The notochord — a mesodermal rod — divides chordates from all non-chordates.

Porifera

Sponges; cellular grade, pores (ostia) and a canal system lined by choanocytes for feeding and gas exchange. Mostly marine — Sycon, Spongilla.

Cnidaria

Radial, diploblastic; stinging cnidoblasts capture prey and defend; a single gastrovascular cavity. Show polyp and medusa forms — Hydra, corals.

Platyhelminthes

Flatworms; dorsoventrally flattened, bilateral, acoelomate; many parasitic with hooks and suckers (Taenia, Fasciola). Flame cells handle excretion.

Aschelminthes

Roundworms; bilateral, triploblastic, pseudocoelomate; frequently parasitic (Ascaris, Wuchereria). Sexes are usually separate and dimorphic.

Annelida

Segmented worms (Nereis, earthworm, leech) with a true coelom, metameric segmentation and closed circulation — first coelomate organ-system phylum.

Arthropoda

The largest phylum; jointed appendages, chitinous exoskeleton and open circulation. Insects, crustaceans and arachnids — Apis, Anopheles, prawn.

Mollusca

Second-largest phylum; soft body with a muscular foot, usually a calcareous shell, a mantle and a rasping radula. Pila, Unio, Octopus, Sepia.

Echinodermata

Marine; spiny skin, calcareous endoskeleton and a water-vascular system with tube feet. Adults radial though the larva is bilateral — starfish, sea urchin.

Chordate hallmarks & classes

Notochord, dorsal hollow nerve cord, pharyngeal gill slits, post-anal tail. Vertebrate classes run from fishes through Amphibia, Reptilia, Aves to Mammalia.