Evaluate Basic External Animal Anatomy and Morphology - AgriSETA

Evaluate Basic External Animal Anatomy and MorphologyPrimary Agriculture NQF Level 1 Unit Standard No: 11617315• The eyesTwo large eyes are situated near the top of the head. Each eye has twomovable eyelids and a membrane, which can move rapidly from thebottom to the top of the eye: it is like a third eyelid (This enables thefrog to clean and protect the eyes from dirt and water).• The earsJust behind each eye there is an eardrum. The ears serve as hearingand balancing organs.• The nostrilsTwo nostrils lie at the front end of the snout. The nostrils are used forsmelling and breathing. The trunkThe trunk forms the greater part of the body. It is flattened from top tobottom and the following are found on the trunk:• The limbsThe fore limbs are short. They consist of an upper arm, a forearm anda hand with four fingers. The hind limbs are long and muscular and aremade up of a thigh, a shin and a foot with five toes. A membraneextends between the toes. This assists the frog in swimming.• The cloacaeThe cloacae (external opening of both the digestive tract and urinarytract) are situated at the rear end of the trunk between the hind limbs.ReproductionThe frog is unisexual (both male and female frogs exist). Females lay eggs inlong strings in the water. The male then discharges sperm over them andfertilisation is therefore external (The sperm and eggs are outside the bodywhen fertilization takes place).BreathingIn the adult stage, the frog breathes primarily by means of two lungs, withlimited help from the skin and the mucous membrane of the mouth. LungsTwo external openings (nares) are linked by means of nasal passages tothe mouth cavity and this gives rise to the pharynx (the part between themouth, nares and throat), which leads in turn to the windpipe. Thewindpipe forks into two bronchi (branches of the windpipe) that lead to thelungs.Version: 01 Version Date: July 2006