Grasshopper Dissection External Observation Locate the head, thorax, and abdomen. Observe the head. Locate the two compound eyes and the three simple eyes. 1. Why do you think grasshoppers have two types of eyes? What could be the difference in their functions? Modeling Instruction AMTA 1 Unit 4 - Energy
2. Use your hand lens to locate the following mouth parts and then describe what their functions could be: Mouth Part Function: What does it do? Labrum Maxillae Labium Mandible Locate the tympanum, or eardrums, on the thorax. All insects have six legs. Locate front legs, middle legs and back legs. 3. What about the structure of the legs enables grasshoppers to survive in their environments? Modeling Instruction AMTA 2 Unit 4 - Energy
4. Locate and label the two pairs of wings. How are wings useful in obtaining food? 5. Find the tiny openings along the abdomen called spiracles. What do spiracles do? Can you drown a grasshopper by holding its head underwater? Internal Observation Remove the three right legs. Insert the point of your scissors under the top surface of the last segment of the abdomen and make a cut to the right of the mid-dorsal line all the way to the head. Be careful not to cut the organs underneath. In front of the thorax cut down the right side to the bottom of the grasshopper. Cut down between the next to the last and last abdominal segments. Remove the exoskeleton from the right side of your grasshopper. Modeling Instruction AMTA 3 Unit 4 - Energy
Locate the large dorsal blood vessel that runs down the grasshopper's body. Remove the muscles of the abdomen. Can you see the air tubes? Carefully cut away muscle and tissue to expose the digestive system. Locate and label the parts of the digestive system: Mouth, Esophagus, Crop, Gizzard, Stomach, Intestine, Rectum, Anus Body Part Function: What does it do? Air Tubes Esophagus Crop Gizzard Stomach Intestine Rectum Anus Modeling Instruction AMTA 4 Unit 4 - Energy
Grasshopper Reading Insects are arthropods (Phylum Arthropoda) with jointed appendages, segmented bodies, and an exoskeleton composed of chitin. Insects are in the class Insecta, & are the largest and most diverse group of animals on earth. Insects have three body regions (head, thorax, & abdomen), 3 pairs of legs attached to the thorax, a single pair of antenna attached to the head and mouthparts adapted for chewing or sucking. Insect legs are often adapted for digging, crawling, jumping, or swimming. Some insects may have a single pair of wings or be wingless. The genus Romalea is a large grasshopper common in the southeastern United States. The development of wings gave grasshoppers advantages over other land invertebrates. They could spread out into new areas, they could search larger areas for food, and they were able to fly away and escape from predators. Grasshoppers have three pairs of jointed legs. The front pair is used for walking, climbing, and holding food. The middle pair is used for walking and climbing. The back pair of legs are used for jumping. Grasshoppers breathe air which enters small lateral openings on the body called spiracles and circulates in a system of ducts to all organs and tissues. Grasshoppers have one pair of antennae that is used for sensing, one pair of large compound eyes that detect movement, and three simple eyes that detect light and dark. Tympanum, or eardrums, on the thorax are used for hearing. The grasshopper's digestive tract is specialized to eat plant tissue. The mouth parts hold, crush, and chew the food before it passes into the mouth. From the mouth the food passes through the esophagus into the crop. The food is stored in the crop. Next, food moves into the gizzard, where teeth made of chitin grind it up further. Food then moves into the intestines where glands digest the food and other structures absorb the digested food. Undigested food then goes to storage in the rectum, and then is eliminated out the anus. Grasshoppers lay a large number of eggs, and the eggs hatch very quickly. This allows the grasshopper population to increase rapidly. Modeling Instruction AMTA 5 Unit 4 - Energy