Phyla Level And Chordates Upto Class Level (1)
Transcript of Phyla Level And Chordates Upto Class Level (1)
CBSE Biology Class 11 I Phyla Level and Chordates up to Class LevelCBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phyla Level and Chordates up to Class Level
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CBSE
B IOLOGY
CLASS
11
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Topics Covered
Phyla Level and Chordates up to Class LevelBasics of Non-Chordates
Phylum - Chordata
Characteristics of Sub-Phylum Vertebrates
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CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Introduction
Based on common fundamental characteristics, the broad classification of Kingdom-Animalia has eleven phyla.
Porifera, Coelenterata, Ctenophora, Platyhelminthes, Aschelminthes, Annelida, Arthropoda, Mollusca, Echinodermata, Hemichordata and Chordata are the phyla divisions.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Basic Characteristics of Non-Chordates
Non-chordates do not have the notochord.
All animals from phylum Porifera to phylum Hemichordata belong to this group.
Non-chordates are classified according to the level of organisation, symmetry and body cavity.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Porifera
Commonly known as sponges, these are
marine, asymmetrical, multi-cellular animals.
They have a cellular level of organisation with a canal
system.
Water enters spongocoel through ostia and leaves
through the osculum.
Collar cells or choanocytes line the
spongocoel and the canals.
A skeleton made of spongin fibres or spicules
supports the body.
Sponges are hermaphrodite and
fertilisation is internal.
Examples are Sycon, Spongilla and Euspongia.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Coelenterata (Cnidaria)
These are marine, sessile and radially symmetrical
animals.
Cnidocites or cnidoblasts present on the body and tentacles give the name
cnidaria.
Cnidoblasts contain nematocytes and help in defence, the capture of prey and anchorage.
Cnidarians possess a gastrovascular cavity
starting at the mouth on hypostome.
Basic body forms are of two types – polyp and
medusa.
Polyps are sessile and cylindrical, for example,
Hydra and Adamsia.
Medusa is umbrella-shaped and free-
swimming, for example, Aurelia.
Corals have a skeleton made of calcium
carbonate.
Cnidarians exhibit metagenesis between polyps and medusa.
Examples are, Physalia, Pennatula, Gorgonia and
Meandrina.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Coelenterata (Cnidaria)
Gorgonia
Physalia
Meandrina
Medusa
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Coelenterata (Cnidaria)Commonly called sea walnuts or comb jellies, these are marine, radially symmetrical organisms.
They are diploblastic with tissue level of organisation of the body.
Locomotion occurs with eight external rows of ciliated comb
plates.
Ctenophores are bioluminescent and digestion is extracellular as well
as intracellular.
Reproduce sexually with external fertilisation.
Examples are, Pleurobrachia and Ctenoplana.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Platyhelminthes
Commonly called flatworms since the body is
dorsoventrally flattened, these are endoparasites.
They are triploblastic, acoelomate, bilaterally symmetrical animals.
Flatworms have organ level of body organisation and
some members can regenerate.
Hooks are suckers are present while some absorb
nutrients from the host through the body surface.
Flame cells help in excretion and osmoregulation.
Internal fertilisation and development show many
larval stages.
Examples are Taenia and Fasciola.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Aschelminthes
Commonly called roundworm,
aschelminthes have a circular cross-section.
They may be aquatic or terrestrial; free-living or
parasitic organisms.
Roundworms are triploblastic,
pseudocoelomate, bilaterally symmetrical
animals.
They have an organ-system level of body
organisation with complete alimentary
canal.
The alimentary canal has muscular pharynx
and excretory canal and excretory pores
remove waste.
Roundworms are dioecious with female longer than males and
internal fertilisation.
Examples are Ascaris, Wuchereria and Ancylostoma.
Ascaris
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Annelida
The name Annelida is from annulus due to segmental division of body known as
metameres.
Annelids may be terrestrial or marine; free-living or
parasitic.
Triploblastic, bilaterally symmetrical, coelomate
organisms, they have organ-system level of organisation.
Aquatic annelids have parapodia for locomotion,
for example, Nereis.
Terrestrial annelids use longitudinal and circular muscles for locomotion.
They have nephridia for excretion and
osmoregulation while having a closed circulatory system.
The neural system consists of double ventral nerve cord connected to paired ganglia
by lateral nerves.
Nereis is dioecious while leech (Hirudinaria) and
earthworm (Pheretima)are monoecious.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Arthropoda
Largest phylum of Animalia, Arthropoda
contains two-third of the classified species.
Triploblastic, segmented, coelomate and bilaterally
symmetrical animals.
They exhibit an organ-system level of organisation
with an open circulatory system.
The body has a head, thorax, abdomen and jointed appendages
covered by a chitinous exoskeleton.
The respiratory system includes gills, book gills and
tracheal system while Malpighian tubules help in
excretion.
Sensory organs include antennae, eyes and
statocysts.
Mostly, dioecious and oviparous, fertilisation is
internal.
Economically important insects are Apis, Bombyx
and Laccifer whereas Limulus is a living fossil.
Disease vectors are Anopheles, Culex and
Aedes while Locusta is a gregarious pest.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Mollusca
The second largest animal phylum, molluscs may be
marine or terrestrial.
They are triploblastic, coelomate, bilaterally
symmetrical organisms with the organ-system level of
organisation.
The body has a head, muscular foot and
visceral hump, but no segmentation.
A soft, spongy layer of skin over the visceral hump is
the mantle with gills below it.
The body has a calcareous shell covering while mouth has a rasping organ called
a radula.
Fully functional respiratory and excretory systems and
the anterior head has sensory tentacles.
Most molluscs are dioecious and oviparous
with indirect development.
Examples are Pila, Sepia, Loligo, Octopus, Pinctada,
Dentalium, Aplysia and Chaetopleura.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Echinodermata
Endoskeleton of calcareous ossicles gives the name Echinodermata.
They are marine, triploblastic, coelomate animals with the organ-
system level of organisation.
Larvae are bilaterally symmetrical while adults are radially symmetrical.
They have a complete digestive system with
ventral mouth and dorsal anus.
Water vascular system helps in locomotion,
respiration, capture and transport of food.
Separate sexes and sexual reproduction is followed by external
fertilisation.
They exhibit indirect development with free-
swimming larvae.
Examples are Asterias, Ophiura, Antedon, Echinus
and Cucumaria.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Hemichordata
Initially considered part of phylum-Chordata,
Hemichordates are now a phylum under non-
chordates.
They are triploblastic, bilaterally symmetrical, coelomate, worm-like
marine animals.
They have organ-system level of organisation with a cylindrical body consisting
of anterior proboscis, collar and a long trunk.
They have an open circulatory system,
respiration is through gills and excretion is through
the proboscis.
They have indirect development after external
fertilisation.
Examples are, Saccoglossus and
Balanoglossus.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Phylum-Chordata
The organisms of this phylum have a
dorsal hollow nerve cord, a notochord
and paired pharyngeal gill
slits.
They are triploblastic, coelomate, bilaterally
symmetrical animals with organ-system
level body organisation.
A closed circulatory
system and post-anal tail are their
other characteristics.
Chordata is divided into three subphyla
Urochordata/Tunicata
Cephalochordata
Vertebrata
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Characteristics of Sub phyla-Urochordata and Cephalochordata
Subphyla Urochordata and Cephalochordata,
called protochordate, are
marine animals.
Notochord is present in larval tail of Urochordata.
Notochord in Cephalochordates
extends from head to tail and remains throughout the
lifespan.
Examples of Urochordates are, Salpa, Ascidia and
Doliolum.
Example of Cephalochordates is
Branchiostoma or Amphioxus.
Amphioxus
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Characteristics of Subphylum-Vertebrata
The notochord during the embryonic stage is
replaced by a vertebral column in adults.
The vertebral column may be bony or cartilaginous.
They have a ventral heart with two, three or
four chambers.
Kidneys help in osmoregulation and
excretion in vertebrates.
Externally, they have paired appendages –
fins or limbs.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Characteristics of Subphylum-Vertebrata
Class division of subphylum-Vertebrata
Agnatha (jawless) Class – Cyclostomata
Gnathostomata (Has jaw)
Superclass – Pisces (has fins)
Class – Chondrichthyes
Class – Osteichthyes
Superclass – Tetrapoda (has limbs)
Class – Amphibia
Class – Reptilia
Class – Aves
Class – Mammalia
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Class – Cyclostomata
Characteristically marine
ectoparasites, they have a
sucking, circular mouth.
They have 6 to 15 pairs of gill
slits but no scales or fins.
Vertebral column and cranium are cartilaginous
while circulation is closed type.
Examples are, Myxine and Petromyzon.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Class – Chondrichthyes
Marine fish with cartilaginous endoskeleton and powerful jaws.
Tough skin with tiny placoid scales with modified placoid as teeth directed backwards.
The notochord is persistent throughout life but no air bladder.
They are poikilothermic (cold-blooded) animals with two-chambered heart.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Class – ChondrichthyesSome members have electric organs, for example Torpedo, and some have poison sting, for example Trygon.
Viviparous animals with internal fertilisation, the males have claspers on pelvic fins.
Examples are, Scoliodon, Carcharodon and Pristis.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Class – Osteichthyes
Both marine and fresh-water fishes, they have a
bony endoskeleton.
Streamlined body with a terminal mouth and skin covered with cycloid or
ctenoid scales.
They have four pairs of gills covered by a pair of
operculum and air bladder to regulate
buoyancy.
They are clod-blooded with two-chambered heart.
Oviparous animals with external fertilisation and
direct development.
Examples of marine Osteichthyes are Exocoetus and Hippocampus.
Freshwater fishes are Labeo, Catla, Clarias etc.
Examples from the aquarium are Pterophyllum
and Betta.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Class – Amphibia
Amphibians have dual life – aquatic as well
as terrestrial.
The body is divided into head and trunk
with two pairs of limbs and tails in some.
Skin is moist, eyes have eyelids and ears
have tympanum.
Respiration occurs through skin and gills
or lungs.
Alimentary canal, urinary and
reproductive tracts open into the cloaca.
Two auricles and one ventricle make a three-chambered
heart for these cold-blooded animals.
They are oviparous with external
fertilisation and indirect development.
Examples are, Hyla, Rana, Bujo,
Salamandra and Ichthyophis.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Class – Reptilia
The name is derived from the Latin word for creep and crawl related to locomotion of these
animals.
Chiefly, terrestrial animals, their bodies have dry, cornified
skin covered with scales or scutes.
They are poikilotherms and heart is three-chambered except in crocodiles (four-
chambered).
Tympanum represents the internal ear while limbs are
two pairs if present.
Oviparous animals with internal fertilisation and direct
development.
Example are Crocodilus, Chameleon, Chelone,
Testudo, Calotes, Hemidactylus, Alligator,
Bangarus, Naja, Vipera etc.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Class – Aves
Aves are animals characterised by forelimbs
modified into wings and body covered by feathers.
Most of them can fly while hind limbs have scales for
swimming, clasping or walking.
Endoskeleton is ossified and long bones have air cavities.
The digestive tract has gizzard, the crop and additional chambers.
They are homeothermic with four-chambered heart and
Respiration is through lungs and supplementary air sacs
help with respiration.
Oviparous animals, they have internal fertilisation and direct
development.
Examples are, Columba, Corvus, Pavo, Psittacula,
Neophron, Struthio, Aptenodytes etc.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Class – Mammalia
The unique characteristic of these animals is the presence
of mammary glands producing milk for young ones.
Most of them have two pairs of limbs and skin covered with
hair.
External ear or pinnae and different types of teeth are
present.
Homeothermic animals, mammals have a four-
chambered heart.
Viviparous animals having internal fertilisation and direct
development.
Examples are, Felis, Canis, Panthera leo, Elephas, Equus,
Macaca, Rattus, Macropus, Delphinus etc.
Ornithorhynchus are oviparous mammals.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Did You Know?
The smallest bird is Mellisugo helenae while the largest bird is Struthio camelus.Struthio is also the fastest runner bird.Fastest swimming bird is Pygoscelis papua.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Q1
When did the reptiles dominate the earth?
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
A1Mesozoic era
The Jurassic period of the Mesozoic era about 200 million years ago was the time for
class-Reptilia dominating the animal world.
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
• The animal kingdom is broadly divided into eleven phyla.• Ten of the phyla are non-chordates while phylum Chordata is the only true chordates.• Porifera are simple multicellular organisms with a cellular level of organisation.• Coelenterates are aquatic, mobile animals having cnidoblasts while Ctenophores have comb plates and are marine.• Platyhelminthes are flat, parasitic worms while Aschelminthes are pseudocoelomate roundworms.• Annelids are coelomate, metamerically segmented animals.• Arthropods are the largest group of animals with a segmented body and a chitinous exoskeleton.• Molluscs are the second-largest animal group with calcareous shell and unsegmented body.• Hemichordates are marine animals with proboscis, collar and trunk.• Chordates have a notochord during development or throughout.• Chordates are divided into classes – Cyclostomata, Chondrichthyes, Osteichthyes, Amphibia, reptilia, Aves and
Mammalia.
Summary
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
The 2-min Test
Question 1: Which type of body scales are present on bony fishes?
Question 2: Describe the mouth of cyclostomes.
Question 3: Name a flightless bird and an oviparous mammal.
Let’s Crack IT!
CBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
The 2-min Test
Question 1: Which type of body scales are present on bony fishes?Answer: Ctenoid or Cycloid scales are present on bony fishes.
Question 2: Describe the mouth of cyclostomes.Answer: A cyclostome has round, sucking mouth without jaws.
Question 3: Name a flightless bird and an oviparous mammal.Answer: Struthio (Ostrich) is a flightless bird and Ornithohynchus (Platypus) is an oviparous mammal.
Let’s Crack IT!
CBSE Biology Class 11 I Phyla Level and Chordates up to Class LevelCBSE Biology Class 11 I Phyla Level and Chordates up to Class Level
Thank you!
CBSE
BIOLOGY
CLASS
11