Class 11th Biology ~ Chapter -4 Animal Kingdom

 

Topics in the Chapter

• Basis of Classification
• Phylum Porifera
• Phylum Coelenterata
• Phylum Ctenophora
• Phylum Plathyhelminthes
• Phylum Aschelminthes
• Phylum Annelida
• Phylum Arthropoda
• Phulum Mollusca
• Phylum Echinodermata
• Phyum Hemichordata
• Phylum Chordata
• Division of Vertebrata
• Super-class: Pisces
• Super Class: Tetrapoda

		1					Symmetry	:		Distribution of body parts around a
		2					hypothetical axis.	:		Ostia : Minute pores on body of sponge.
		3					Osculum	:		Large outlet in body of sponge.
		4					Hermaphrodite	:		Bisexual.
		5					Polyp	:		Sessile cylindrical form of coelenterate (Asexual).
		6					Medusa	:		Umbrella shaped free swimming sexual stage of coelenterate.
		7					Acoelomate	:		No coelom.
		8					Pseudocoelom	:		With false coelom (cavity not underlined by mesoderm).
		9					Dioecious	:		Unisexual.
		10					Operculum	:		Cover over gills in fish
		11					Notochord	:		Dorsal rod like bone
		12					Homoiotherms	:		Warm blooded.
		13					Bioluminescence	:		Emit light

-Levels of organisation

		i)	Cellular level- loose cell aggregates, small division of labour eg. Sponges
		ii)	Tissues grouped into organs eg.
Coelenterate.
		iii)	Organ level-Tissues grouped into organs eg. Higher animals.
Circulatory system
		a)	Open type- No blood vessels, blood flows in sinuses.
		b)	Close type- Blood flows in closed vessels.
Symmetry
		-	Asymmetrical – No symmetry eg. Sponges.
		-
		-	Radial Symmetry – Any plane passing through central axis divides body in two equal halves.
		-	Bilateral Symmetry – Body can be divided into two equal halves through one plane only.
Diploblastic and Triploblastic organisation –
		-	Two embryonic layers – Ectoderm and Endoderm – Diploblastic.
		-	Three embryonic layers- Ectoderm, Mesoderm and endoderm- Triploblastic.
Coelom –
		-	Body cavity lined by mesoderm- True Coelom.
		-	Body cavity not lined by mesoderm Pseudo Coelom.
		-	No body cavity – Acoelomate.
Segmentation –
		-	True segments- Metameres (Body divided internally and externally).
Notochord –
		-	With notochord – Chordates.
		-	Without notochord – Non-Chordates.
	Classification of Animals –

Phylum Porifera –
		-	Marine.
		-	Multicellular, cellular grade body.
		-	Asymmetrical.
		-	Water canal system for food, respiration and excretion.
		-	Body wall with many pores – Ostia.
		-	Diploblastic.
		-	Water enters through Ostia and goes out through Osculum.
		-	Skeleton of spicules or spongin fibres.
		-	Hermaphrodite.
		-	Reproduction asexual by fragmentation and sexual by gametes.
		-	Fertilisation is internal, development indirect.
		-	eg. Sycon, Spongilla, Euspongiaetc.
Phylum Coelenterata (Cnidaria) –
		-	Aquatic (marine), Sessile or free living.
		-	Presence of Cnidoblasts or Cnidocytes – Stinging cells.
		-	Cnidoblasts are for defence, anchorage or predation.
		-	Tissue level body organisation.
		-	Diploblastic.
		-	Central gastro vascular cavity, single opening mouth.
		-	Two body forms – Polyp (Asexual), Medusa (Sexual) stage.
		-	eg Hydra, Physalia, Obelia, Aurelia etc.
Phylum Ctenophora (sea walnuts or comb jellies) –
		-	Marine, radial symmetry, Diploblastic, tissue grade.
		-	Eight external rows of Comb Plates.
		-	Bioluminescence.
		-	eg. Ctenoplana, Pleurobrachia etc.
		-	Reproduction sexual.
Phylum Platehelminthes (Flat worms) –
		-	Body dorsiventrally flattened.
		-	Endoparasite.
		-	Triploblastic, bilateral symmetry.
		-	Acoelomate
		-	-Flame cells- for excretion & osmoregulation.
		-	-Flame cells- for excretion & osmoregulation.
		-	Hermaphrodite
		-	Reproduction – Sexual - Fertilisation internal.
		-	Organ level organisation.
		-	eg. Taeniasolium(Tape worm), Fasciola hepatica (liver fluke).
Phylum Aschelminthes (Round Worm) –
		-	Free living or parasitic, aquatic and terrestrial. Bilateral symmetry and Triploblastic.
		-	Pseudocoelomate. Muscular pharynx.
		-	Male smaller and thinner than female. Fertilisation internal, development direct or indirect.
		-	eg. Ascarislumbricoides, Wucherariabancroftiietc.
Phylum Annelida –
		-	Aquatic or terrestrial.
		-	Free living or parasitic.
		-	Organ system level body bilateral symmetry and Triploblastic coelomate.
		-	Nephridia for excretion.
		-	Ventral double Nerve cord.
		-	Monoecious or Dioecious.
		-	Reproduction – Sexual. eg.
		-	Earthworm(Pheretima),Nereis etc.
		-	Metameric segmentation.
Phylum Arthropoda( Jointed Legs) –
		-	Largest phylum.
		-	Bilateral symmetry, Triploblastic, segmented coelomate.
		-	Body - Head, Thorax and Abdomen(three parts).
		-	Blood without haemoglobin and circulatory system open.
		-	Respiration by gills, book lungs and trachea.
		-	Excretion by malpighian tubules.
Phylum Mollusca –
		-	Soft body animals. Second largest phylum.
		-	Aquatic, bilateral symmetry, triploblastic, coelomate. Body unsegmented divided into head, muscular foot and visceral hump.
		-	Soft mantle over visceral hump. Respiration and excretion through gills.
		-	Unisexual.
		-	Sensory tentacles on head and Radula in mouth.
		-	Oviparous.
		-	-eg.Pila, Octopus etc
PHYLUM  ECHINODERMATA
		-	Body surface spiny, (due to calcareous ossicles)
		-	Marine , organ system level, adult radially symmetrical, triploblastic coelomate.
			Mouth ventral
		1	Water vascular system present for locomotion, capture and transport of food and respiration.
		2	Sexes separate fertilization external, development indirect
		-	e.g.  Asterias (Starfish), Sea urchin (Echinus), etc.
PHYLUM HEMICHORDATA
		1	Marine
		2	Bilateral symmetry, triploblastic, coelomate
		3	Body
		i	Proboscis
		ii	Collar
		iii	Trunk
		4	Circulatory system open
		5	Gills for respiration
		6	Proboscis gland for excretion
			Sexes separate fertilization external, development indirect, e.g. Balanoglossus.
PHYLUM- CHORDATA
Distinguishing features
		1	Presence of Notochord
		2	Dorsal hollow nerve cord
		3	Paired pharyngeal gills slits
		4	Post anal tail present
		5	Heart is ventral
	SUB PHYLA –
		1	Urochordata or Tunicata, Notochord only in larval tail  e.g.  Ascidia
		2	Cephalochordata notochord head to tail in all stage  e.g. Branchiostoma
		3	Vertebrata:  Notochord replaced by a vertebral column.
SUB PHYLUM- VERTEBRATA
AGNATHA-without jaw
		CLASS- Cyclostomata-
		Ectoparasite on fish
		-	C ircular mouth
		-	No scales and paired fins
		-	Marine but go in fresh water for spawning and die. Larva returns to ocean.
		-	Eg. Petromyzon, Myxine.
Gnathostomata – with jaws
		Class - Chondrichthyes
		-	Aquatic and terrestrial both.
		-	Two pairs of limbs.
		-	No neck.
		-	Body has head and trunk only.
		-	No external ear, tympanum on surface.
		-	Heart three chambered.
		-	Cloaca present.
		-	Respiration by gills, skin and lungs.
		-	Sexes separate.
		-	Fertilisation external, development direc
		-	eg. Ranatigrina, Bufo, Hyla etc.
Class Reptilia –
		-	Creeping or crawling mode of locomotion.
		-	Skin with scales/scutes.
		-	Tympanum on surface.
		-	Heart three chambered (Four chambered in crocodile).
		-	Fertilisation internal, development direct.
		-	eg. Chelone, Testudo, Naja, Hemidactylus etc.
Class Aves –
		-	presence of feather, beak and forelimb in form of wing.
		-	Hind limb adapted to clasping, walking and swimming.
		-	No glands on skin (only oil gland at tail base).
		-	Hollow bones (pneumatic).
		-	Air sacs connected to lungs to supplement respiration.
		-	Crop and gizzard are additional chambers in digestive system.
		-	Warm blooded.
		-	Heart four chambered.
		-	Sexes separate.
		-	Fertilisation internal and development direct.eg.
		-	Columba, Psittacula etc.
Class Mammalia –
		-	Aquatic, terrestrial and aerial.
		-	Mammary glands present for milk production.
		-	Two pairs of limbs.
		-	Skin with hair.
		-	Ear with pinna.
		-	Homoiothermic.
		-	Heart four chambered.
		-	Excretion by kidneys.
		-	.Sexes separate.
			Internal fertilisation, vivipary (exception Platypus).
		-	eg. Whale, Rat , Man, Tiger etc.
		-	Respiration by lungs

Biology Class 11th: Chapter - 4 Animal Kingdom  Question Answer