🌿 Grade 9 Science · Biology

Samacheer Class 9 Science - Animal Kingdom

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34 Questions

Complete Grade 9 Science questions and answers for Animal Kingdom. Click any question to expand the answer.

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📋 Sections in this chapter
I. Choose the Correct AnswerII. Fill in the BlanksIII. State Whether True or FalseIV. Match the FollowingV. Answer Very BrieflyVI. Answer BrieflyVII. Answer in DetailIntext ActivitiesActivity – 1
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1I. Choose the Correct Answer10 questions

Q.1Which group contains only marine animals?
✓ Answer
  • (a) Mollusca
  • (b) Coelenterata
  • (c) Echinodermata
  • (d) Porifera

Answer:
(c) Echinodermata


Q.2Mesoglea is present in
✓ Answer
  • (a) Porifera
  • (b) Coelenterata
  • (c) Annelida
  • (d) Arthropoda

Answer:
(b) Coelenterata


Q.3Which pair is not poikilothermic?
✓ Answer
  • (a) Fishes and Amphibians
  • (b) Amphibians and Aves
  • (c) Aves and Mammals
  • (d) Reptiles and Mammals

Answer:
(c) Aves and Mammals

Birds and mammals are warm-blooded (homeothermic).

Q.4Animal with four-chambered heart is
✓ Answer
  • (a) Lizard
  • (b) Snake
  • (c) Crocodile
  • (d) Calotes

Answer:
(c) Crocodile


Q.5Animal without skull is
✓ Answer
  • (a) Acrania
  • (b) Acephalia
  • (c) Apteria
  • (d) Acoelomate

Answer:
(a) Acrania


Q.6Hermaphrodite organisms are
✓ Answer
  • (a) Hydra, Tapeworm, Earthworm, Amphioxus
  • (b) Hydra, Tapeworm, Earthworm, Ascidian
  • (c) Hydra, Tapeworm, Earthworm, Balanoglossus
  • (d) Hydra, Ascaris, Earthworm

Answer:
(b) Hydra, Tapeworm, Earthworm, Ascidian


Q.7Poikilothermic organisms are
✓ Answer
  • (a) Fish, Frog, Lizard, Man
  • (b) Fish, Frog, Lizard, Crow
  • (c) Fish, Frog, Lizard, Snake
  • (d) Fish, Frog, Lizard, Crow

Answer:
(c) Fish, Frog, Lizard, Snake


Q.8Air sacs and pneumatic bones are present in
✓ Answer
  • (a) Fish
  • (b) Frog
  • (c) Bird
  • (d) Bat

Answer:
(c) Bird


Q.9Excretory organ of tapeworm is
✓ Answer
  • (a) flame cells
  • (b) nephridia
  • (c) body surface
  • (d) solenocytes

Answer:
(a) Flame cells


Q.10Water vascular system occurs in
✓ Answer
  • (a) Hydra
  • (b) Earthworm
  • (c) Starfish
  • (d) Ascaris

Answer:
(c) Starfish



2II. Fill in the Blanks0 questions
  • Skeletal framework of Porifera is made of spicules.
  • Ctenidia are respiratory organs in molluscs.
  • Skates are cartilaginous fishes.
  • Larva of amphibians is bilaterally symmetrical.
  • Cyclostomes are jawless vertebrates.
  • Placenta is characteristic feature of mammals.
  • Spiny anteater is an example of egg-laying mammal.


3III. State Whether True or False9 questions

If false, correct the statement.


Q.1Canal system is seen in coelenterates.
✓ Answer

Answer: False

Correct Statement:
Canal system is seen in Porifera.


Q.2Hermaphrodites possess both male and female reproductive organs.
✓ Answer

Answer: True


Q.3Trachea is respiratory organ of annelids.
✓ Answer

Answer: False

Correct Statement:
Trachea is respiratory organ of arthropods.


Q.4Bipinnaria is larva of Mollusca.
✓ Answer

Answer: False

Correct Statement:
Bipinnaria is larva of starfish (Echinodermata).


Q.5Balanoglossus is a ciliary feeder.
✓ Answer

Answer: True


Q.6Fishes have two-chambered heart.
✓ Answer

Answer: True


Q.7Skin of reptiles is smooth and moist.
✓ Answer

Answer: False

Correct Statement:
Skin of amphibians is smooth and moist.


Q.8Wings of birds are modified forelimbs.
✓ Answer

Answer: True


Q.9Female mammals possess mammary glands.
✓ Answer

Answer: True



4IV. Match the Following0 questions
PhylumExample
CoelenterataHydra
PlatyhelminthesTapeworm
EchinodermataStarfish
MolluscaSnail


5V. Answer Very Briefly7 questions

Q.1Define Taxonomy
✓ Answer

Answer:

Taxonomy is branch of biology dealing with identification, naming and classification of organisms.


Q.2What is Nematocyst?
✓ Answer

Answer:

Stinging cells present in coelenterates are called nematocysts or cnidoblasts.

They help in:

  • protection
  • capturing prey

Q.3Why are Coelenterates Called Diploblastic?
✓ Answer

Answer:

Their body wall consists of two germ layers:

  • Ectoderm
  • Endoderm

These are separated by mesoglea.

Hence they are called diploblastic animals.


Q.4Respiratory Organs of Amphibians
✓ Answer

Answer:

Respiration occurs through:

  • gills
  • skin
  • buccopharynx
  • lungs

Q.5Locomotion in Starfish
✓ Answer

Answer:

Locomotion occurs by tube feet with help of water vascular system.


Q.6Are Jellyfish and Starfish True Fishes?
✓ Answer

Answer:

No.

  • Jellyfish belongs to Coelenterata.
  • Starfish belongs to Echinodermata.

Both are invertebrates.

True fishes are vertebrates.

Correction made:
Jellyfish body is not made of calcium carbonate.

Q.7Why are Frogs Called Amphibians?
✓ Answer

Answer:

Frogs live both in water and on land.

Hence they are called amphibians.



6VI. Answer Briefly6 questions

Q.1Account of Phylum Annelida
✓ Answer

Answer:

Features:

  • Bilaterally symmetrical
  • Triploblastic
  • True coelomates
  • Body divided into segments
  • Covered by moist cuticle
  • Setae/parapodia used for locomotion
  • Sexes may be separate or united

Examples:

  • Earthworm
  • Leech
  • Nereis

Q.2Differentiate Flatworms and Roundworms
✓ Answer
FlatwormsRoundworms
Phylum PlatyhelminthesPhylum Aschelminthes
AcoelomatePseudocoelomate
Mostly hermaphroditeSexes separate
Flat bodyCylindrical body
Simple alimentary canalComplete alimentary canal
Example: TapewormExample: Ascaris

Q.3Outline of Phylum Chordata
✓ Answer

# Chordata

(i) Protochordata

  • Urochordata
  • Cephalochordata

(ii) Vertebrata

  • Pisces
  • Amphibia
  • Reptilia
  • Aves
  • Mammalia

Q.4Five Features of Fishes
✓ Answer

Answer:

  • Aquatic vertebrates
  • Cold-blooded
  • Body streamlined
  • Respiration by gills
  • Locomotion by fins
  • Heart is two-chambered

Types of Fishes

Cartilaginous fishes

Example:

  • Shark
  • Skate

Bony fishes

Example:

  • Carp
  • Mullet

Q.5Aquatic and Terrestrial Adaptations of Amphibians
✓ Answer

# Aquatic Adaptations

  • Tadpole lives in water
  • Gills used for respiration
  • Webbed feet for swimming
  • External fertilization

# Terrestrial Adaptations

  • Adults live on land
  • Respiration by lungs
  • Limbs adapted for hopping

Q.6Bird Limb Adaptations
✓ Answer

Answer:

  • Forelimbs modified into wings
  • Feathers help in flight
  • Hind limbs adapted for:
  • walking
  • perching
  • swimming


7VII. Answer in Detail2 questions

Q.1Characteristics of Protochordates
✓ Answer

# Protochordata

Primitive chordates considered ancestors of vertebrates.


Urochordata

  • Notochord only in larval tail
  • Adults are sessile
  • Body covered by tunic

Example:

Ascidian


Cephalochordata

  • Fish-like marine animals
  • Notochord extends throughout body

Example:

Amphioxus


Q.2Account of Phylum Arthropoda
✓ Answer

Features

  • Largest animal phylum
  • Bilaterally symmetrical
  • Triploblastic and coelomate
  • Body divided into:
  • head
  • thorax
  • abdomen
  • Jointed appendages present
  • Exoskeleton made of chitin
  • Moulting occurs
  • Open circulatory system
  • Respiration by:
  • gills
  • tracheae
  • body surface
  • Excretion by Malpighian tubules or green glands

Examples

  • Cockroach
  • Crab
  • Spider
  • Scorpion
  • Prawn
  • Centipede


8Intext Activities0 questions


9Activity – 10 questions

Identify Arthropods

OrganismGroup
ScorpionArachnid
SpiderArachnid
CockroachInsect
CrabCrustacean
PrawnCrustacean

# Important Summary


Porifera

  • Canal system
  • Spicules

Coelenterata

  • Diploblastic
  • Nematocysts

Platyhelminthes

  • Flatworms
  • Flame cells

Annelida

  • Segmented worms

Arthropoda

  • Jointed legs
  • Chitinous exoskeleton

Mollusca

  • Soft-bodied
  • Ctenidia

Echinodermata

  • Water vascular system

Chordata

  • Notochord present
  • Vertebrates included

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