Welcome Dr. Mohammad Nurul Hoque Head of the Department Department of Science English Version Cambrian School & college

Chordata, Vertebrata and Necessity of classification Chapter ONE Lesson: 6-8

Lesson Outcome Say what is chordata Say what is vertebrata After this lesson students will able to… Explain the importance of classification

1. Arboreal 2. Cave-dwelling 3. Dorsal 4. Persist 5. Cartilaginous Important words

Chordata General characteristics (1) The notochord is a rod-like unsegmented semi rigid structure that forms a stiffening. body axis throughout life or at some stage in the life cycle of each chordate. (2) Single, dorsal, tubular nerve cord is present. (3) Pharyngeal pouches (gill slits) is present throughout life or at some stages in the life cycle. Example : Man, Toad, Carp (Rui) fish

Chordata UrochordataCephalochordata Vertibrata Cyclostomata Chondrichthyes Osteicthyes Amphibia Reptilia Aves Mammalia

Urochordata General characteristics 1. Notochord is present only in larval stage and restricted to the tail. 2. Gill slits and dorsal tubular nerve cord are present only in the early stage of the life cycle. Example : Ascidia, Salpa.

Cephalochordata General Characteristics 1. Notochord and nerve cord are found along the entire length of body and persist throughout life. 2. Commonly known as lancelets. Example: Branchiostoma

Cyclostomata (1) True jaws and paired appendages are absent. (2) Fish like in form. (3) Body slender, eel-like, rounded with naked skin. Example : Petromyzon

Chondrichthyes (1) All marine. (2) Cartilaginous skeleton. (3) Skin with placoid scales; 5-7 pairs of gills are present on both side of the head. (4) Streamlined body with heterocercal tail but no operculum. Example: Shark, Sword fish, Hammer Fish

Osteicthyes General characteristics (1) Mostly fresh water fish. (2) Skin with cycloid, ctenoid or ganoid scales; some without scale. (3) Respiration primarily by gills. Four pair of gills are present on both side of the head. Gills are covered by operculum. Example : Hilsa fish, Sea horse.

Amphibia General characteristics (1) Skin without scales. (2) Skin thin, soft, moist and with many glands. (3) Amphibians are cold-blooded animal. (4) They lay eggs in water. A tadpole hatches from the fertilized egg. Example : Frog, Toad.

Reptilia General characteristics (1) Skin dry and with scales. (2) They move by crawling. (3) Limbs paired, usually with five toes; absent in snakes and some lizards. Example:Wall lizard, Crocodile, Snake.

Aves General characteristics (1) Body is covered with feather. (2) Fore limbs usually modified for flying; and jaws forming a beak. (3) The presence of air sacs with lung helps in flight. (4) All birds are warm blooded. (5) Bones are light, strong, delicate and laced with air cavities. Example : Crow, Duck, Magpie.

Mammalia General characteristics (1) Body covered with hair. (2) Female mammal suckle their young on milk from mammary glands. (3) Warm blooded animal (4) Four-chambered heart. (5) Teeth heterodont (Varying in structure and function). (6) With a few exceptions all give birth to child. Example : Man, Camel, Royal Bengal Tiger.

Necessity of the Classification of animal kingdom

Class Work Find out the answers of given MCQs

Home Work Solve the Creative Question -2

ASSIGNMENT Do the provided assignment sheet

Thank You