• The chordates occupy the best position in the food sequence.
• The name phylum was derived from the characteristic which in turn all chordates share, the notochord – a long, elongated, and flexible cartilaginous structure that runs the entire length of the body system. (Gr. noto = the back; chorde = string)
• A hinten nerve cord located above the notochord, that runs the whole length of the body system. The neurological cord is actually a bundle of nerve fibres that links the brain for the different parts of the entire body.
• Presence of pharyngeal slits which are openings between the neck and the outside the house it's also modified to filtering food and gaseous exchange. The pharyngeal slits happen to be supported by gill arches which in turn also had been greatly altered.
• Occurrence of post-anal tail, an extension of notochord that stretches beyond the anus.
• They are bilaterally symmetrical human body plan.
• Important: It differentiates all of them from other family pets is the existence of two appendages. These kinds of appendages are really modified intended for locomotion.
Several Groups of Chordates:
• Invertebrate chordates
-are the chordates whose notochords remain through the entire life with the organisms.
• Vertebrate chordates
-are the chordates which have notochord and pharyngeal slits during early stages of development.
• Cephalochordota(cephalo = head)
- Is definitely represented by the lancelet or perhaps amphioxus, a chordate having a fishlike physical appearance.
-Is a unique chordate that lives mounted on the seabed. The going swimming larva in the organism provides the notochord, and everything the rest of the unique features of the chordates.
Vertebrate chordates(7 classes)
Three Classes of Fish:
• Course Agnatha(a sama dengan not, with out; gnathos sama dengan jaw).
-This is displayed by the lamprey, an eel shaped jawless fish that is certainly considered as the vampire of the ocean.
• Class Chondrichthyes(chondro = the fibrous connective tissue cartilage, ichthyes = fish).
-The fish with cartilaginous endoskeleton.
• Course Osteichthyes(osten = bone; ichthyes = fish).
-Class of bony these people own in.
• Amphibia(amphios = in both sides, twice; bios = life).
-Named because the larval part of the your life of the amphibians is spent in drinking water and the mature is in land.
• Reptilia(repere = to creep).
-have body covered with dry, cornified scales. All their eggs are leathery.
• Aves(aves = birds).
-have bodies covered with feathers, scaly ft that are adapted to the sort of environment that they live.
• Mammalia(mamma = breasts).
-the presence of breasts can be described as distinguishing feature of mammals. Their breasts are well created to produce dairy. Their physiques are covered with hair.
Subclasses of mammalia:
a. Monotremata(trema sama dengan hole).
- have body covered with thick fur.
-They're chest that lack nipples yet secrete dairy.
-unique since they are the only egg-laying(oviparous) mammals.
w. Marsupials(marsupium sama dengan bag or perhaps pouch.
-the marsupium is made up of nipples that secrete milk.
-The youthful is born immaturely and crawls in the sack.
c. Placental Mammals
-where the youthful is nourished as it undergoes development till birth. The biggest and the most diverse sort of chordates.
Several Orders of Placental Mammals
|Order |Characteristics |Representatives | |Rodentia |Presence of razor-sharp chisel like teeth. |Rats, mice, squirrels, etc . | |Insectivora |Presence of a lengthy snout employed for devouring |Moles,...