Protochordates and Vertebrates: Characters.pptx

Protochordates and Vertebrates: Characters.pptx

• 1.
  CHAPTER : 4 PROTOCHORDATA and VERTEBRATA Chapter:4 Pranabjyoti Das
• 2.
  11/18/2024 Pranabjyoti Das 2 PROTOCHORDATA Protochordatais one of the groups of phylum chordata. Protochordata constitutes the marine, small, primitive, or lower chordates. The members of protochordates lack a head, skull or cranium, true vertebral column and brain. About 2000 species are found in this group.
• 3.
  11/18/2024 Pranabjyoti Das 3 They are generally found in marine water.  Their body is bilaterally symmetrical, triploblastic, and coelomate.  They exhibit organ system level of organization.  At a certain stage of their lives, their body develops a long, rod-like structure for support called the notochord. Characteristics of Protochordata
• 4.
  11/18/2024 Pranabjyoti Das 4 Protochordateis classified into three kinds of sub-phyla based on the type of notochord they possess. They are: Hemichordata, Urochordata and Cephalochordata Classification
• 5.
  11/18/2024 Pranabjyoti Das 5 HEMICHORDATA The body of hemichordates is worm-like, thus they are commonly called worm animals.  They have a bilaterally symmetrical body and are triploblastic in nature.  They have a true coelom.  Proboscis, collar, and trunk are the three main parts of the body.  Gill slits are present that perforate the pharynx.  From the roof of the buccal cavity a buccal diverticulum or stomochord arises. Examples of hemichordates include Balanoglossus, Saccloglossus, etc.
• 6.
  11/18/2024 Pranabjyoti Das 6 UROCHORDATA They are found in the marine environment.  They are known as tunicates as their body is covered by a leathery sheath composed of tunicin  The notochord appears in the larval stage in the tail of the larva and disappears in the adult.  This is known as retrogressive metamorphosis.  Respiration occurs through gills.  They have an open circulatory system.  The excretory organs are absent. Example : Herdmania, Salpa
• 7.
  11/18/2024 Pranabjyoti Das 7 Chepalochordata They are marine and filter-feeders.  The notochords remain throughout life and extend up to the head region.  The nerve cord and the tail also remain throughout life.  Solenocytes are the excretory organs.  They respire through gills which open in the atrium.  The body wall comprises myotomes. Example: Amphioxux
• 8.
  11/18/2024 Pranabjyoti Das 8 VERTEBRATA
• 9.
  11/18/2024 Pranabjyoti Das 9
• 10.
  11/18/2024 Pranabjyoti Das 10 Vertebrateshave the following general characteristics  Backbone: Vertebrates have a backbone that provides support and allows for movement.  Nervous system: Vertebrates have a central nervous system, including a brain and spinal cord.  Circulatory system: Vertebrates have a closed circulatory system.  Skin: Vertebrates have skin that is protected by hair, feathers, or scales.  Muscles: Vertebrates have muscles attached to their skeleton and work to control movement.  Endocrine system: Vertebrates have an endocrine system that secrete hormones.  Excretory system: Vertebrates have a pair of kidneys that filter waste from the blood.  Immune system: Vertebrates have an adaptive immune system to defend the pathogens.
• 11.
  11/18/2024 Pranabjyoti Das 11 PISCESor FISHES  They have a streamlined body.  The circulatory system is of close type.  The body has three regions- head, trunk, and tail.  The skeleton can be bony or cartilaginous.  The sexes are separate.  A well-developed digestive system is present.  Paired and unpaired fins are present  Breaths through gills.  They are oviparous  They are cold blooded
• 12.
  11/18/2024 Pranabjyoti Das 12 Classificationof Fish: All fish species found across the world are divided into three classes. They are as follows:  Agnatha - jawless fish  Chrondrichthyes - cartilaginous fish  Osteichthyes - bony fish
• 13.
  11/18/2024 Pranabjyoti Das 13 AGNATHA Agnathans are fish with no jaws and no paired fins.  They also don't have an internal skeletal system.  They have a circular mouth with teeth (cyclostomata)  With these teeth, they bore their victim's body and suck their blood.  There are two primary categories of them and they are known as Hagfish and Lampreys.
• 14.
  11/18/2024 Pranabjyoti Das 14 CHONDRICHTHYES Chrondrichthyes are both fearsome predators and mollusk eaters.  They have powerful jaws with sharp teeth.  The member of these fishes have both real bone and a cartilage skeleton.  Only the teeth and, in rare cases, the vertebrae of this species are calcified.  The Chondrichthyes are a group of sharks, skates, and rays. Examples : Sharks and Rays
• 15.
  11/18/2024 Pranabjyoti Das 15 OSTEICHTHYES This species of fishes are spindle shaped in form, oval in section, and flattened.  Skin is covered by protective scales.  Some fish in this group have true lungs to breathe and have excellent eyesight.  To stay buoyant, these bony fishes have a an air bladder  Paired and unpaired fins are present.
• 16.
  11/18/2024 Pranabjyoti Das 16 AMPHIBIA
• 17.
  11/18/2024 Pranabjyoti Das 17 REPTILIA They have a 3 chambered heart except crocodiles.  They are oviparous and development is direct.  They have 12 pairs of cranial nerves in their nervous system.  Internal fertilization.  No external ear opening.  They are uricotelic and excrete nitrogenous waste in the form of uric acid.  Lay eggs on land and can leave in water.  They have four legs but always touch the belly on ground while moving.
• 18.
  11/18/2024 Pranabjyoti Das 18 AVES Birds are warm-blooded animals.  Their forelimbs are modified into wings.  They have well-developed flight muscles that help during the flight.  Their hind limbs are adapted for walking, hopping, perching.  There are epidermal scales on their legs.  The endoskeleton is bony with air cavities  Their spindle-shaped body minimizes resistance of the wind.  The feathers help in preventing heat loss.  Feathers also reduce air friction during flight  There is no skin gland except the oil gland.  The lower and upper and jaws are modified into a beak.  They have no teeth. AVES
• 19.
  11/18/2024 Pranabjyoti Das 19 Mammals are warm-blooded animals who give birth to their younger ones.  They are the most dominant form of animals found in almost all types of habitats.  They have mammary glands that help them produce milk to feed their younger ones  Brain is wel developed.  Their skin possesses oil glands and sweat glands.  The fur of hair throughout the body which helps animals adapt to their environment.  They are heterodont, i.e., possess different types of teeth.  Mammals possess cervical vertebrae.  The mammals respire through lungs.  Mammals have a four-chambered heart.  The sinus venous and renal portal system are absent in circulatory system . MAMMALIA