NEET · CLASS 11 · CHAPTER 4 · COMPLETE
Animal Kingdom
Full Chapter Revision Sheet · Strictly New NCERT
Created by BioMaster · Private Notes
Introduction Porifera Cnidaria Ctenophora Platyhelminthes Aschelminthes Annelida
Arthropoda Mollusca Echinodermata Hemichordata Chordata
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🔬 Introduction — Basis of Classification NCERT PG. 55–60
s te
a
LE VELS OF ORGANISATION SYMME TRY
M
→ Cellular — cells as loose aggregates → Asymmetrical — no plane (Porifera)
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level (Porifera) → Radial — any plane through central axis
→ Tissue — cells of same type form tissue (Cnidaria, Ctenophora, adult
B
level (Cnidaria) Echinodermata)
→ Organ — tissues form organs → Bilateral — only one plane (Platyhelminthes
level (Platyhelminthes) onwards)
→ Organ-system — organs form systems (most
level animals)
GERM L AYERS COELOM
→ Diploblastic — ectoderm + endoderm; → Acoelomate — no body cavity (Platyhelminthes)
mesoglea between (Porifera, → Pseudocoelomate — body cavity NOT lined by
Cnidaria, Ctenophora) mesoderm on all sides
→ Triploblastic — ectoderm + mesoderm + (Aschelminthes)
endoderm (Platyhelminthes → Coelomate — true coelom lined by mesoderm
onwards) (Annelida onwards)
SEGMENTATION NOTOCHORD
→ Body divided into repetitive segments → Mesodermally derived rod-like structure on
(metameres) externally and internally dorsal side
,→ Seen in Annelida, Arthropoda and Chordates → Present at some stage in Chordates only
→ Hemichordates stomochord — NOT a true
have notochord
N O N - C H O R D ATA
🧽 Phylum Porifera
Phylum Porifera Asymmetrical Cellular Level Diploblastic
Sponges · "Pore Bearers"
Mostly marine; Spongilla is freshwater Body has ostia (pores) → spongocoel →
osculum
Canal system — food gathering, respiration,
te r
Choanocytes (collar cells) — line spongocoel;
s
waste removal create water current
a
Skeleton: spicules (calcareous/siliceous) or Digestion intracellular
M
spongin fibres
io
Hermaphrodite; asexual by fragmentation; High regeneration — totipotent cells
B
sexual by gametes (archaeocytes)
NCERT E XAMPLES
Sycon (Scypha) Spongilla (freshwater) Euspongia (Bath sponge)
🪼 Phylum Cnidaria (Coelenterata)
, Phylum Cnidaria Radial Symmetry Tissue Level Diploblastic
Jellyfish, Corals, Hydra · "Stinging cells"
Aquatic, mostly marine; Hydra is freshwater Cnidoblasts / nematocysts — defence,
anchorage, prey capture
Central gastrovascular cavity (coelenteron); Digestion: intracellular + extracellular
single opening (mouth)
Polyp — sessile, asexual | Medusa — free- Metagenesis — alternation of polyp & medusa
swimming, sexual (Obelia)
Corals — calcareous exoskeleton; some colonial Reproduction: sexual & asexual; fertilisation
external; development indirect
🧠 NEVER CONFUSE
r
POLYP = sessile, tubular, asexual (budding) → produces medusae | MEDUSA = free-swimming, umbrella-
te
shaped, sexual → produces polyp
NCERT E XAMPLES
a s
M
Physalia (Portugese man-of-war) Adamsia (sea anemone) Pennatula (sea pen) Gorgonia (sea fan)
io
Meandrina (brain coral) Obelia (metagenesis)
✨ Phylum Ctenophora B
Animal Kingdom
Full Chapter Revision Sheet · Strictly New NCERT
Created by BioMaster · Private Notes
Introduction Porifera Cnidaria Ctenophora Platyhelminthes Aschelminthes Annelida
Arthropoda Mollusca Echinodermata Hemichordata Chordata
r
🔬 Introduction — Basis of Classification NCERT PG. 55–60
s te
a
LE VELS OF ORGANISATION SYMME TRY
M
→ Cellular — cells as loose aggregates → Asymmetrical — no plane (Porifera)
io
level (Porifera) → Radial — any plane through central axis
→ Tissue — cells of same type form tissue (Cnidaria, Ctenophora, adult
B
level (Cnidaria) Echinodermata)
→ Organ — tissues form organs → Bilateral — only one plane (Platyhelminthes
level (Platyhelminthes) onwards)
→ Organ-system — organs form systems (most
level animals)
GERM L AYERS COELOM
→ Diploblastic — ectoderm + endoderm; → Acoelomate — no body cavity (Platyhelminthes)
mesoglea between (Porifera, → Pseudocoelomate — body cavity NOT lined by
Cnidaria, Ctenophora) mesoderm on all sides
→ Triploblastic — ectoderm + mesoderm + (Aschelminthes)
endoderm (Platyhelminthes → Coelomate — true coelom lined by mesoderm
onwards) (Annelida onwards)
SEGMENTATION NOTOCHORD
→ Body divided into repetitive segments → Mesodermally derived rod-like structure on
(metameres) externally and internally dorsal side
,→ Seen in Annelida, Arthropoda and Chordates → Present at some stage in Chordates only
→ Hemichordates stomochord — NOT a true
have notochord
N O N - C H O R D ATA
🧽 Phylum Porifera
Phylum Porifera Asymmetrical Cellular Level Diploblastic
Sponges · "Pore Bearers"
Mostly marine; Spongilla is freshwater Body has ostia (pores) → spongocoel →
osculum
Canal system — food gathering, respiration,
te r
Choanocytes (collar cells) — line spongocoel;
s
waste removal create water current
a
Skeleton: spicules (calcareous/siliceous) or Digestion intracellular
M
spongin fibres
io
Hermaphrodite; asexual by fragmentation; High regeneration — totipotent cells
B
sexual by gametes (archaeocytes)
NCERT E XAMPLES
Sycon (Scypha) Spongilla (freshwater) Euspongia (Bath sponge)
🪼 Phylum Cnidaria (Coelenterata)
, Phylum Cnidaria Radial Symmetry Tissue Level Diploblastic
Jellyfish, Corals, Hydra · "Stinging cells"
Aquatic, mostly marine; Hydra is freshwater Cnidoblasts / nematocysts — defence,
anchorage, prey capture
Central gastrovascular cavity (coelenteron); Digestion: intracellular + extracellular
single opening (mouth)
Polyp — sessile, asexual | Medusa — free- Metagenesis — alternation of polyp & medusa
swimming, sexual (Obelia)
Corals — calcareous exoskeleton; some colonial Reproduction: sexual & asexual; fertilisation
external; development indirect
🧠 NEVER CONFUSE
r
POLYP = sessile, tubular, asexual (budding) → produces medusae | MEDUSA = free-swimming, umbrella-
te
shaped, sexual → produces polyp
NCERT E XAMPLES
a s
M
Physalia (Portugese man-of-war) Adamsia (sea anemone) Pennatula (sea pen) Gorgonia (sea fan)
io
Meandrina (brain coral) Obelia (metagenesis)
✨ Phylum Ctenophora B
