Abstract: People have always wondered how frogs have the capability to live in both wet and dry environments. So why not dissect a frog to find out how. Frogs have both physical features like their skin that allows them to breath in water. They also have anatomical features like humans that allow them breath air just like us. Introduction As many people have learned throughout elementary and middle school amphibians are animals that have the physical capabilities to live in water and on land.
Sarah Wilkes states that the amphibian derived from the Greek word amphibious, meaning “double life” (4). There are several types of amphibians which include frogs, toads, newts, salamanders, and caecilians. They are classified as vertebrates. They have a vertebral column, which is a series of small bones that run down their back to provide support. The same column can be found in mammals, birds and reptiles (Wilkes 4). Amphibians breathe through their moist skin as well as their lungs.
They have long sticky tongues and they have ears but are internal unlike mammals. They smell using the roof of their mouth using a nerve called the Jacobson’s organ. They mostly have limbs similar to mammals but with different features. They have four digits on their front limbs and five digits on their hind limbs (Wilkes 4). Amphibians go through a series of physical changes called metamorphosis. Frogs lay eggs that hatch into larvae, called tadpoles that live in water and slowly change into small frogs (Wilkes 5).
Since frogs are classified as amphibians do they have same anatomical features as other amphibians that allow them to live comfortably in both water and dry environments? This will be tested by conducting a frog dissection to identify to organs needed to survive in both environments. Methods In order to conduct this experiment you will need a frog, preferably dead, a clean organized work station, a dissecting pan, pins, scissors. The first thing you need to do is clean the frog off and lay it in the dissecting pan.
Next you will examine the external features of the frog, such as the forelegs and hind legs of the frog. Next examine the eyes of the frog. Pay close attention to the nictitating membrane that covers and protects the eye like the eyelid of a human. Then notice the tympanic membrane located behind the eye. Next you should open the frogs’ mouth. Notice how the frog has a set of internal nares called nostrils. Next you should notice the eustachian tube found in the angles of the jaw. This helps the tympanic membrane equalize pressure when the frog is diving.
Food will enter the stomach through the esophagus. The lungs get air from the glottis which lies in front of the esophageal opening. The frog has two sets of teeth. The set at the top of the mouth are called vomerine teeth. The teeth located around the edge of the mouth are called maxillary teeth. Now you should lay the frog on its back in the dissecting pan. Then you will cut all the way through the middle of the frog. Then make two more cuts across the frog allowing you to pin the muscles back to see the internal structures. You should see three lobes of liver.
There will be a left anterior, left posterior and right liver lobe. The heart is located toward the top of the liver and has two upper chambers called the left and right atrium. The ventricle is the lower chamber. The artery that delivers the blood to the rest of the body is called the Conus Arteriosus. The lungs are located under the liver and tend to look spongy. Also located under the liver is the gall bladder stores bile. You should also be able to see the stomach where the food begins to digest. It leads to the small intestine.
The straight part of the small intestine is called the duodenum that leads to the ileum. The spleen is off to the side of the stomach. Cloaca which means sewer serves as the large intestine to discard the food, sperm, and eggs exit the body. After examining the frog more if you like you can discard the frog and wash or throw away other materials used. Results The frog has several organs for them to be such small creatures. They have lungs, intestines, gall bladders, and livers. They have nostrils and tongues and eyes very similar to human anatomy. They have anatomical eatures that allow them to discard food, and eggs. Discussion After examining the necessary organs to live in both water and dry land environments it can be determined that frogs have the anatomical and physical features needed to survive in both places. Frogs breathe through their moist skin to allow them to live in the water because they don’t have to use lungs for oxygen. Their skin can become camouflage to allow them to hide from predators seeking prey. They also have a set of nostrils which allows them to live on land so that they can get oxygen to their lungs.