The Chordates p 767 Background Members of the phylum chordate are called _____________. Four characteristics of all chordates: 1. 2. 3. 4. Most chordates are vertebrates Most vertebrates have: -Strong supporting structure known as the ___________ ____________ or ___________ -The dorsal hollow nerve cord is called the ___________ ____________ -The front end of the spinal cord develops into a ________________ - The backbone in most vertebrates is made up of individual segments called ___________ -Vertebrae provide _________ and enclose and __________ the __________ __________ Amphibians –The Frog p782 I. Amphibian and frog characteristics What does amphibian mean? Why is this good description of an amphibian? A. Background 1. An amphibian is a _______________ 2. Most amphibians live in _________ as a larva and on __________ as an adult 3. Breaths with _____________ as an adult 4. Has ______________ skin with mucus glands 5. Lacks ______________ and ________________ II. External characteristics 1. the frog has a short, broad body with two short ________ and two long muscular ___________ _________ 2. the upper surface is __________ -_____________ in color and the underside is _______________ in color WHY? 3. two large movable eyes protrude like periscopes permitting vision in all__________________ 4. each eye is protected by three eyelids the nictitating membrane is transparent which allows the frog to see underwater 5. behind each eye is its ear the _____________ ___________________ 6. the two nostrils on the tip of the head enable the frog to breath air while the rest of the body is underwater 7. the frog has both vomerine teeth and maxillary teeth -the vomerine teeth are slanted inwards why? -the eyesockets are used to keep the living prey in the frogs mouth. III. Internal features of the frog- amphibians A. Digestive (Feeding) -The mouth of the frog is very large WHY? -The esophagus is elastic WHY? - Food passes from the mouth through the gullet to the esophagus and then into the ____________ - The digestion of food begins in the _______________ - The partially digested food then passes into the small _________________ where ____________ continues and food is ____________________Tubes connect the intestine with the _____________ , _______________ and gallbladder that secrete substances that aid in _________________ Does food enter the pancreas? - Most digestion and absorption occur in the small_______________ Undigested food enters the _______________ _____________ or colon From the large intestine food enters the ______________ a muscular cavity which serves as a passageway for digestive waste, _____________ and ___________ or _______________. B. Respiratory System - The tadpole- organs of respiration_________________ - The ADULT - the exchange of gases occurs through the ________________, lining of the mouth and the skin - these structures contain small blood vessels called capillaries where oxygen moves into the blood stream and carbon dioxide out of the blood stream C. Circulatory System -The frog has a ________ chambered heart. - It has two _____________ and one _____________ - arteries lead away from the heart - veins lead toward the heart - Blood that leaves the _______________ is a mixture of oxygenated and deoxygenated blood - What is oxygenated blood? -What is deoxygenated blood? D. Excretory System - amphibians have ____________ that filter wastes from the blood - the excretory product of the kidneys- ______________ - travels through tubes called _____________ - From the ureters urine moves into the ______________ - urine may then move directly to the outside or it may be stored in a small __________________ ________________ just above the cloaca E. Reproduction - in the female the ______________ are located along the back of the kidneys -large numbers of _____________ enter the oviducts which are coiled tubes -the eggs are stored in sacs until they are released through the cloaca -their eggs are surrounded by a transparent jelly that ______________ the egg mass to underwater plants and makes the _____________ difficult for predators to grasp - the yolk of the egg nourishes the developing embryos until they hatch into larvae called ___________________ - Male o Testes are small yellowish bean shaped organs o Sperm pass into the kidneys o From the kidneys the sperm are carried by the ureters to the cloaca o During mating(amplexus) the sperm are released from the male through the cloaca o During mating the male helps the female release her eggs by pushing with his large thumb pads F. fertilization and Development - most amphibians have ________________ fertilization -the eggs are released as the male releases his sperm Advantage -baby frogs are called ______________ process of change into and adult___________________ G. Nervous System (Response)p 787 & p862 - vertebrates display a high degree of ___________________, or concentration or sense organs and nerve cells at the front of the body - the head contains a well developed brain and spinal cord both of which are a part of the central nervous system - the vertebrate brain is subdivided into several parts, the __________________, __________________, _____________ ______________, optic lobes, and _______________ ______________ - the medulla oblongata controls many internal organs -the optic lobes are involved in ______________ - the olfactory lobes are involved in the sense of ______________ p 787 - large eyes - nictitating membrane which protects the eye from _______________ under water and keeps the eye ____________ while on land -tympanic membrane allows a frog to _______________ Classification Kingdom ________________________ Phylum__________________________ Class ___________________________ Order __________________________ Genus _________________________ Species ________________________
