Important Questions Class 11 Biology Chapter 4: Animal Kingdom With Answers

Animal Kingdom is the classification of multicellular heterotrophic organisms based on body organisation and body plan. Animals differ in symmetry, germ layers, coelom, segmentation, notochord, and organ systems.

Animal classification becomes simple when each group is identified by one decisive feature. Sponges show cellular organisation, cnidarians have cnidoblasts, flatworms are acoelomates, annelids show metamerism, arthropods have jointed appendages, and chordates have a notochord. Important Questions Class 11 Biology Chapter 4 test the basis of classification, non-chordate phyla, chordate characters, vertebrate classes, and NCERT exercise patterns for CBSE 2026.

Key Takeaways

• Over One Million Species: More than one million animal species have been described till now.
• Arthropoda: Over two-thirds of all named species on earth are arthropods.
• Chordata Rule: Notochord, dorsal hollow nerve cord, and pharyngeal gill slits define chordates.
• Echinodermata: Adult echinoderms show radial symmetry, but their larvae show bilateral symmetry.

Important Questions Class 11 Biology Chapter 4 Structure 2026

Important Questions Class 11 Biology Chapter 4: Key Concepts

These class 11 biology chapter 4 important questions cover the basic terms used in animal classification. Most long answers begin from these features.

Q1. What Is Animal Kingdom In Class 11 Biology?

Animal Kingdom includes multicellular heterotrophic organisms classified by body organisation, symmetry, coelom, segmentation, and notochord.

1. Main Basis:
   Structure, body plan, and organ systems.
2. Major Division:
   Non-chordates and chordates.
3. Final Result:
   Animal Kingdom classifies animals using common fundamental features

Q2. Why Is Animal Classification Important?

Animal classification is important because over one million animal species have been described till now.

1. Main Need:
   It organises animal diversity.
2. Scientific Use:
   It assigns systematic position to new species.
3. Final Result:
   Classification helps identify and compare animals

Q3. What Are The Main Bases Of Animal Classification?

The main bases are level of organisation, symmetry, germ layers, coelom, segmentation, and notochord.

1. Body Plan:
   Symmetry and segmentation.
2. Internal Structure:
   Coelom and germ layers.
3. Chordate Feature:
   Notochord.
4. Final Result:
   Animal classification uses structural and developmental features

Q4. What Are Levels Of Organisation In Animal Kingdom?

Levels of organisation show how cells form tissues, organs, and organ systems.

1. Cellular Level:
   Porifera.
2. Tissue Level:
   Coelenterata.
3. Organ Level:
   Platyhelminthes.
4. Organ System Level:
   Annelida to Chordata.
5. Final Result:
   Higher animals show organ system organisation

Q5. What Is Symmetry In Animals Class 11?

Symmetry means body division into equal halves through a plane.

1. Asymmetry:
   Sponges.
2. Radial Symmetry:
   Coelenterates, ctenophores, adult echinoderms.
3. Bilateral Symmetry:
   Annelids, arthropods, chordates.
4. Final Result:
   Symmetry helps identify body plan

Q6. What Are Diploblastic And Triploblastic Animals?

Diploblastic animals have two germ layers, while triploblastic animals have three germ layers.

1. Diploblastic Layers:
   Ectoderm and endoderm.
2. Triploblastic Layers:
   Ectoderm, mesoderm, and endoderm.
3. Final Result:
   Mesoderm separates triploblastic animals from diploblastic animals

Q7. What Is Coelom Class 11 Biology?

Coelom is a body cavity lined by mesoderm. It lies between body wall and gut wall.

1. Coelomates:
   Annelids, molluscs, arthropods, echinoderms, chordates.
2. Pseudocoelomates:
   Aschelminthes.
3. Acoelomates:
   Platyhelminthes.
4. Final Result:
   Coelom is a major classification feature

Q8. What Is Metameric Segmentation?

Metameric segmentation is serial repetition of body segments. Earthworm shows this pattern.

1. External Division:
   Body has repeated segments.
2. Internal Division:
   Some organs repeat serially.
3. Final Result:
   Metamerism first appears clearly in annelids

Q9. What Is Notochord?

Notochord is a mesodermally derived rod-like structure on the dorsal side during development.

1. Present In:
   Chordates.
2. Absent In:
   Non-chordates.
3. Final Result:
   Notochord separates chordates from non-chordates

Animal Kingdom Class 11 MCQ With Answers

These animal kingdom class 11 MCQ questions cover NCERT facts. They help revise phylum-wise features for CBSE 2026.

Q1. Which Phylum Shows Cellular Level Of Organisation?

Porifera shows cellular level of organisation.

1. Options:
   (A) Porifera
   (B) Cnidaria
   (C) Annelida
   (D) Chordata
2. Rule Used:
   Sponges have loose cell aggregates.
3. Final Result:
   Answer: (A) Porifera

Q2. Cnidoblasts Are Found In Which Phylum?

Cnidoblasts are found in Cnidaria.

1. Options:
   (A) Porifera
   (B) Cnidaria
   (C) Mollusca
   (D) Echinodermata
2. Rule Used:
   Cnidoblasts help in anchorage, defence, and prey capture.
3. Final Result:
   Answer: (B) Cnidaria

Q3. Comb Plates Are Found In Which Group?

Comb plates are found in Ctenophora.

1. Options:
   (A) Ctenophora
   (B) Platyhelminthes
   (C) Aschelminthes
   (D) Annelida
2. Rule Used:
   Ctenophores have eight rows of ciliated comb plates.
3. Final Result:
   Answer: (A) Ctenophora

Q4. Flame Cells Are Found In Which Phylum?

Flame cells occur in Platyhelminthes.

1. Options:
   (A) Porifera
   (B) Platyhelminthes
   (C) Arthropoda
   (D) Mollusca
2. Rule Used:
   Flame cells help in osmoregulation and excretion.
3. Final Result:
   Answer: (B) Platyhelminthes

Q5. Which Phylum Is Pseudocoelomate?

Aschelminthes is pseudocoelomate.

1. Options:
   (A) Platyhelminthes
   (B) Aschelminthes
   (C) Annelida
   (D) Echinodermata
2. Rule Used:
   Its body cavity lacks complete mesodermal lining.
3. Final Result:
   Answer: (B) Aschelminthes

Q6. Which Phylum Shows Metameric Segmentation?

Annelida shows metameric segmentation.

1. Options:
   (A) Cnidaria
   (B) Platyhelminthes
   (C) Annelida
   (D) Ctenophora
2. Rule Used:
   Earthworm shows repeated body segments.
3. Final Result:
   Answer: (C) Annelida

Q7. Which Is The Largest Phylum Of Animalia?

Arthropoda is the largest phylum of Animalia.

1. Options:
   (A) Mollusca
   (B) Arthropoda
   (C) Chordata
   (D) Annelida
2. Rule Used:
   Over two-thirds of named species are arthropods.
3. Final Result:
   Answer: (B) Arthropoda

Q8. Water Vascular System Is Found In Which Phylum?

Water vascular system is found in Echinodermata.

1. Options:
   (A) Porifera
   (B) Ctenophora
   (C) Echinodermata
   (D) Chordata
2. Rule Used:
   It helps in locomotion, food capture, transport, and respiration.
3. Final Result:
   Answer: (C) Echinodermata

Q9. Which Structure Is Present In Hemichordata?

Stomochord is present in Hemichordata.

1. Options:
   (A) Notochord
   (B) Stomochord
   (C) Radula
   (D) Operculum
2. Rule Used:
   Balanoglossus has a stomochord in the collar region.
3. Final Result:
   Answer: (B) Stomochord

Q10. Mammary Glands Are Found In Which Class?

Mammary glands are found in Mammalia.

1. Options:
   (A) Aves
   (B) Reptilia
   (C) Mammalia
   (D) Amphibia
2. Rule Used:
   Mammals nourish young ones with milk.
3. Final Result:
   Answer: (C) Mammalia

Basis Of Classification Class 11 Biology Important Questions

Basis of classification class 11 biology questions are usually asked as short answers. They test body plan, body cavity, organ systems, and development.

Q1. Distinguish Between Open And Closed Circulatory Systems.

Open circulation bathes tissues directly, while closed circulation keeps blood inside vessels.

1. Open Type:
   Blood leaves the heart and directly bathes cells.
2. Closed Type:
   Blood flows through arteries, veins, and capillaries.
3. Final Result:
   Closed circulation allows more controlled blood flow

Q2. Distinguish Between Incomplete And Complete Digestive Systems.

An incomplete digestive system has one opening, while a complete digestive system has two openings.

1. Incomplete System:
   One opening acts as mouth and anus.
2. Complete System:
   Separate mouth and anus occur.
3. Final Result:
   Complete digestion has separate entry and exit openings

Q3. What Is Radial Symmetry?

Radial symmetry means any plane through the central axis divides the body into equal halves.

1. Examples:
   Coelenterates, ctenophores, echinoderms.
2. Body Plan:
   Parts radiate from central axis.
3. Final Result:
   Radial symmetry occurs around a central axis

Q4. What Is Bilateral Symmetry?

Bilateral symmetry means only one plane divides the body into equal left and right halves.

1. Examples:
   Annelids and arthropods.
2. Body Plan:
   Left and right sides mirror each other.
3. Final Result:
   Bilateral symmetry supports directional movement

Q5. Distinguish Between Coelomate, Pseudocoelomate, And Acoelomate Animals.

Coelomates have true coelom, pseudocoelomates have false coelom, and acoelomates lack body cavity.

1. Coelomate:
   Body cavity lined by mesoderm.
2. Pseudocoelomate:
   Body cavity not fully mesoderm-lined.
3. Acoelomate:
   Body cavity absent.
4. Final Result:
   Coelom type separates major animal groups

Q6. How Useful Is Coelom In Animal Classification?

Coelom is useful because it separates animals by body cavity organisation.

1. Platyhelminthes:
   Acoelomate.
2. Aschelminthes:
   Pseudocoelomate.
3. Annelida Onwards:
   Coelomate.
4. Final Result:
   Coelom helps trace structural complexity

Non Chordata Class 11 Questions

Non chordata class 11 questions cover phyla from Porifera to Hemichordata. These animals lack notochord.

Q1. Write The Important Features Of Phylum Porifera.

Porifera includes sponges with cellular organisation and a canal system.

1. Habitat:
   Mostly marine.
2. Water Flow:
   Ostia to spongocoel to osculum.
3. Digestion:
   Intracellular.
4. Examples:
   Sycon, Spongilla, Euspongia.
5. Final Result:
   Porifera has pores, canals, and choanocytes

Q2. What Is The Canal System In Sponges?

Canal system is the water transport pathway in sponges.

1. Entry:
   Water enters through ostia.
2. Cavity:
   Water reaches spongocoel.
3. Exit:
   Water leaves through osculum.
4. Final Result:
   Canal system supports feeding, respiration, and waste removal

Q3. What Are Choanocytes?

Choanocytes are collar cells lining spongocoel and canals.

1. Location:
   Spongocoel and canals.
2. Function:
   Maintain water current and food capture.
3. Final Result:
   Choanocytes are characteristic cells of Porifera

Q4. Write The Important Features Of Phylum Cnidaria.

Cnidaria includes aquatic animals with cnidoblasts and tissue-level organisation.

1. Symmetry:
   Radial.
2. Germ Layers:
   Diploblastic.
3. Digestion:
   Extracellular and intracellular.
4. Examples:
   Hydra, Aurelia, Adamsia, Obelia.
5. Final Result:
   Cnidaria has cnidoblasts and gastrovascular cavity

Q5. What Is Metagenesis In Cnidaria?

Metagenesis is alternation between polyp and medusa forms.

1. Polyp:
   Produces medusa asexually.
2. Medusa:
   Produces polyp sexually.
3. Example:
   Obelia.
4. Final Result:
   Metagenesis occurs in cnidarians with both forms

Q6. Write The Important Features Of Phylum Ctenophora.

Ctenophores are marine animals with comb plates and bioluminescence.

1. Common Name:
   Sea walnuts or comb jellies.
2. Symmetry:
   Radial.
3. Reproduction:
   Sexual only.
4. Examples:
   Pleurobrachia, Ctenoplana.
5. Final Result:
   Ctenophora has comb plates for locomotion

Q7. Write The Important Features Of Phylum Platyhelminthes.

Platyhelminthes includes dorsoventrally flattened acoelomate animals.

1. Symmetry:
   Bilateral.
2. Germ Layers:
   Triploblastic.
3. Excretion:
   Flame cells.
4. Examples:
   Taenia, Fasciola.
5. Final Result:
   Platyhelminthes are flatworms

Q8. What Are Peculiar Features Of Parasitic Platyhelminthes?

Parasitic platyhelminthes have hooks, suckers, and nutrient absorption through body surface.

1. Attachment:
   Hooks and suckers.
2. Nutrition:
   Direct absorption from host.
3. Development:
   Many larval stages.
4. Final Result:
   Parasitic flatworms show attachment adaptations

Q9. Write The Important Features Of Phylum Aschelminthes.

Aschelminthes includes roundworms with pseudocoelom and complete alimentary canal.

1. Body Shape:
   Circular in cross-section.
2. Sexes:
   Separate.
3. Example:
   Ascaris, Wuchereria, Ancylostoma.
4. Final Result:
   Aschelminthes are roundworms

Q10. Write The Important Features Of Phylum Annelida.

Annelida includes coelomate animals with metameric segmentation.

1. Organisation:
   Organ-system level.
2. Circulation:
   Closed type.
3. Excretion:
   Nephridia.
4. Examples:
   Nereis, Pheretima, Hirudinaria.
5. Final Result:
   Annelids are segmented coelomates

Q11. What Are Parapodia?

Parapodia are lateral appendages in aquatic annelids. They help in swimming.

1. Example:
   Nereis.
2. Function:
   Locomotion in water.
3. Final Result:
   Parapodia are swimming appendages

Q12. Why Do Arthropods Form The Largest Animal Phylum?

Arthropods form the largest phylum because they have jointed appendages, chitinous exoskeleton, and diverse habitats.

1. Protection:
   Chitinous exoskeleton.
2. Movement:
   Jointed appendages.
3. Adaptation:
   Varied respiratory organs.
4. Final Result:
   Arthropods show high survival diversity

Q13. Write The Important Features Of Phylum Arthropoda.

Arthropoda includes bilaterally symmetrical coelomates with jointed appendages.

1. Body Division:
   Head, thorax, abdomen.
2. Circulation:
   Open type.
3. Excretion:
   Malpighian tubules.
4. Examples:
   Apis, Bombyx, Laccifer, Locusta, Limulus.
5. Final Result:
   Arthropoda has jointed appendages

Q14. Write The Important Features Of Phylum Mollusca.

Mollusca includes soft-bodied coelomate animals usually covered by a calcareous shell.

1. Body Parts:
   Head, muscular foot, visceral hump.
2. Feeding Organ:
   Radula.
3. Examples:
   Pila, Pinctada, Sepia, Octopus.
4. Final Result:
   Mollusca is the second largest animal phylum

Q15. What Is Radula?

Radula is a file-like rasping organ in molluscs. It helps in feeding.

1. Location:
   Mouth.
2. Phylum:
   Mollusca.
3. Final Result:
   Radula is a feeding organ of molluscs

Q16. Write The Important Features Of Phylum Echinodermata.

Echinodermata includes marine animals with calcareous ossicles and water vascular system.

1. Adult Symmetry:
   Radial.
2. Larval Symmetry:
   Bilateral.
3. Excretion:
   Excretory system absent.
4. Examples:
   Asterias, Echinus, Antedon, Ophiura.
5. Final Result:
   Echinoderms have water vascular system

Q17. Write The Important Features Of Phylum Hemichordata.

Hemichordata includes worm-like marine animals with proboscis, collar, and trunk.

1. Body Structure:
   Cylindrical.
2. Respiration:
   Gills.
3. Excretion:
   Proboscis gland.
4. Examples:
   Balanoglossus, Saccoglossus.
5. Final Result:
   Hemichordata has stomochord, not notochord

Chordata Class 11 Important Questions

Chordata class 11 important questions focus on notochord, dorsal hollow nerve cord, pharyngeal gill slits, and vertebrate classification.

Q1. Write The Main Features Of Phylum Chordata.

Chordates have notochord, dorsal hollow nerve cord, and paired pharyngeal gill slits.

1. Other Features:
   Post-anal tail and closed circulation.
2. Body Plan:
   Bilateral, triploblastic, coelomate.
3. Final Result:
   Chordata is defined by notochord and dorsal nerve cord

Q2. Distinguish Between Chordates And Non-Chordates.

Chordates have notochord, while non-chordates lack notochord.

1. Chordates:
   Dorsal hollow nerve cord and pharyngeal gill slits occur.
2. Non-Chordates:
   Ventral solid nerve cord may occur.
3. Final Result:
   Notochord is the key difference

Q3. What Are Protochordates?

Protochordates are marine chordates under Urochordata and Cephalochordata.

1. Urochordata:
   Notochord present only in larval tail.
2. Cephalochordata:
   Notochord extends from head to tail.
3. Examples:
   Ascidia, Salpa, Doliolum, Branchiostoma.
4. Final Result:
   Protochordates are primitive marine chordates

Q4. Why Are All Vertebrates Chordates But All Chordates Are Not Vertebrates?

All vertebrates are chordates because they possess notochord during embryonic life. All chordates do not develop vertebral column.

1. Vertebrates:
   Notochord is replaced by vertebral column.
2. Protochordates:
   Vertebral column is absent.
3. Final Result:
   Vertebral column separates vertebrates from other chordates

Q5. What Are The Main Features Of Vertebrata?

Vertebrates have notochord during embryonic life and vertebral column in adults.

1. Heart:
   Ventral muscular heart.
2. Excretion:
   Kidneys.
3. Appendages:
   Fins or limbs.
4. Final Result:
   Vertebrata has vertebral column in adult stage

Vertebrata Class 11 Biology Important Questions

Vertebrata class 11 biology questions test Cyclostomata, Pisces, Amphibia, Reptilia, Aves, and Mammalia. These groups are important for comparison-based questions.

Q1. Write The Features Of Cyclostomata.

Cyclostomata includes jawless ectoparasites on fishes.

1. Mouth:
   Sucking and circular.
2. Body:
   No scales and paired fins.
3. Examples:
   Petromyzon and Myxine.
4. Final Result:
   Cyclostomes are jawless vertebrates

Q2. Write The Features Of Chondrichthyes.

Chondrichthyes includes marine fishes with cartilaginous endoskeleton.

1. Mouth:
   Ventral.
2. Scales:
   Placoid scales.
3. Air Bladder:
   Absent.
4. Examples:
   Scoliodon, Pristis, Carcharodon, Trygon.
5. Final Result:
   Chondrichthyes are cartilaginous fishes

Q3. Write The Features Of Osteichthyes.

Osteichthyes includes marine and freshwater fishes with bony endoskeleton.

1. Gills:
   Four pairs covered by operculum.
2. Air Bladder:
   Present.
3. Examples:
   Exocoetus, Hippocampus, Labeo, Catla, Clarias.
4. Final Result:
   Osteichthyes are bony fishes

Q4. Why Is Air Bladder Important In Pisces?

Air bladder regulates buoyancy in bony fishes. It helps them stay at desired water depth.

1. Present In:
   Osteichthyes.
2. Absent In:
   Chondrichthyes.
3. Final Result:
   Air bladder helps bony fishes avoid sinking

Q5. Write The Features Of Amphibia.

Amphibians can live in aquatic and terrestrial habitats.

1. Skin:
   Moist and without scales.
2. Heart:
   Three-chambered.
3. Respiration:
   Gills, lungs, and skin.
4. Examples:
   Bufo, Rana, Hyla, Salamandra, Ichthyophis.
5. Final Result:
   Amphibians show dual life

Q6. Write The Features Of Reptilia.

Reptiles are mostly terrestrial animals with dry cornified skin.

1. Heart:
   Usually three-chambered, four-chambered in crocodiles.
2. Fertilisation:
   Internal.
3. Examples:
   Chelone, Testudo, Chameleon, Crocodilus, Naja.
4. Final Result:
   Reptiles have dry scales or scutes

Q7. Write The Features Of Aves.

Aves have feathers, beak, and forelimbs modified into wings.

1. Bones:
   Hollow pneumatic bones.
2. Heart:
   Four-chambered.
3. Respiration:
   Lungs with air sacs.
4. Examples:
   Crow, pigeon, parrot, ostrich, peacock, penguin.
5. Final Result:
   Aves are warm-blooded birds

Q8. What Modifications Help Birds Fly?

Birds fly due to wings, feathers, hollow bones, and air sacs.

1. Forelimbs:
   Modified into wings.
2. Skeleton:
   Hollow pneumatic bones.
3. Respiration:
   Air sacs support lungs.
4. Final Result:
   Bird flight depends on light body and efficient respiration

Q9. Write The Features Of Mammalia.

Mammals have mammary glands, hair, external ears, and four-chambered heart.

1. Reproduction:
   Mostly viviparous.
2. Respiration:
   Lungs.
3. Examples:
   Platypus, kangaroo, bat, camel, dog, dolphin, whale, tiger.
4. Final Result:
   Mammals nourish young ones with milk

Q10. Why Are Mammals Unique?

Mammals are unique because they possess mammary glands and hair.

1. Mammary Glands:
   Nourish young ones.
2. Hair:
   Present on skin.
3. Final Result:
   Mammary glands are the key mammalian feature

Animal Kingdom Class 11 NCERT Questions

These animal kingdom class 11 NCERT questions follow exercise patterns. Use them for school tests and CBSE 2026 revision.

Q1. What Difficulties Arise If Fundamental Features Are Not Used In Animal Classification?

Classification becomes confusing without fundamental features. Animals with similar appearance may differ in body organisation, coelom, and notochord.

1. Problem:
   External form alone may mislead.
2. Better Basis:
   Symmetry, coelom, segmentation, and organ systems.
3. Final Result:
   Fundamental features make classification scientific

Q2. What Steps Help Classify An Animal Specimen?

A specimen can be classified by checking body organisation, symmetry, germ layers, coelom, segmentation, and notochord.

1. Step 1:
   Check level of organisation.
2. Step 2:
   Check symmetry and coelom.
3. Step 3:
   Check notochord and phylum features.
4. Final Result:
   Classification follows observable structural features

Q3. Distinguish Between Intracellular And Extracellular Digestion.

Intracellular digestion occurs inside cells, while extracellular digestion occurs in a cavity or canal.

1. Intracellular Digestion:
   Food digests inside cells.
2. Extracellular Digestion:
   Food digests outside cells in digestive space.
3. Final Result:
   Sponges show intracellular digestion

Q4. What Is The Difference Between Direct And Indirect Development?

Direct development lacks larval stage, while indirect development includes larval stage.

1. Direct Development:
   Young one resembles adult.
2. Indirect Development:
   Larva differs from adult.
3. Final Result:
   Larval stage defines indirect development

Q5. Why Do Arthropods Constitute The Largest Group Of Animal Kingdom?

Arthropods are largest due to jointed appendages, exoskeleton, segmentation, and wide adaptations.

1. Exoskeleton:
   Protects body.
2. Jointed Appendages:
   Improve movement and feeding.
3. Respiratory Diversity:
   Gills, book lungs, and tracheae occur.
4. Final Result:
   Arthropods dominate animal diversity

Q6. Water Vascular System Is Characteristic Of Which Group?

Water vascular system is characteristic of Echinodermata.

1. Given Options:
   Porifera, Ctenophora, Echinodermata, Chordata.
2. Correct Option:
   Echinodermata.
3. Final Result:
   Answer: Echinodermata

Q7. How Important Is Air Bladder In Pisces?

Air bladder helps bony fishes maintain buoyancy.

1. Present In:
   Osteichthyes.
2. Function:
   Prevents sinking and supports floating.
3. Final Result:
   Air bladder regulates buoyancy

Q8. Could Oviparous And Viviparous Mothers Produce Equal Numbers Of Young Ones?

They usually do not produce equal numbers. Oviparous animals generally produce more eggs because external development has higher risk.

1. Oviparous Animals:
   Eggs develop outside the mother.
2. Viviparous Animals:
   Young ones develop inside the mother.
3. Final Result:
   Viviparity gives better protection to fewer young ones

Q9. Segmentation Is First Observed In Which Phylum?

Segmentation is first observed in Annelida.

1. Given Options:
   Platyhelminthes, Aschelminthes, Annelida, Arthropoda.
2. Correct Option:
   Annelida.
3. Final Result:
   Answer: Annelida

Q10. Match The Following Animal Features.

The correct matching links each structure to its animal group.

1. Operculum:
   Osteichthyes.
2. Parapodia:
   Annelida.
3. Scales:
   Reptilia.
4. Comb Plates:
   Ctenophora.
5. Radula:
   Mollusca.
6. Hairs:
   Mammalia.
7. Choanocytes:
   Porifera.
8. Gill Slits:
   Cyclostomata and Chondrichthyes.
9. Final Result:
   a-viii, b-v, c-iv, d-i, e-ii, f-vii, g-iii, h-vi

Q11. List Animals Parasitic On Human Beings.

Several animals live as parasites on human beings.

1. Flatworms:
   Taenia and Fasciola.
2. Roundworms:
   Ascaris, Wuchereria, Ancylostoma.
3. Arthropods:
   Mosquitoes and lice.
4. Final Result:
   Human parasites occur across many phyla