Invertebrates ARTHROPODA INSECTS Kingdom-Animalia Phylum-Arthropods SubPhylum-Hexapods Class-Insects

INSECTS Insects have bilateral symmetry Insects are coelomate meaning they have body captivity they are tribloblastic meaning they have an ectoderm layer, mesoderm layer, and endoderm layer. It displays cephalization and this is when the head becomes the most complex structure on the insect They are protostomes meaning their mouth develops first through gastrulation Many insects but not all go through a larva stage much different than their adult stage and to get from one point to the other they must go through metamorphosis which involes a pupal stage and basically remodels the organism There are many orders of the class insects which include Blattodea for an example a german cockroach would be under this category, Hymenoptera for an example a bee would be under this category and then also phthiraptera which a stick insect would fall in this category, and also another class would be siphonaptera which has a flea under this category.

INSECTS cont. DIGESTIVE SYSTEM- The insect digestive system is a closed system, with one long enclosed tube (alimentary canal) running lengthwise through the body. Alimentary canal contains: foregut (stomodaeum)-initial breakdown of large food particles occurs, mostly by saliva midgut (mesenteron)- digestion through enzymatic action; microvilli, increase surface area and allow for maximum absorption of nutrients. hindgut (proctodaeum)- rectum absorbs most of the water in this waste matter, and the dry pellet is then eliminated through the anus

INSECTS cont. NERVOUS SYSTEM- consists primarily of a brain, located dorsally in the head, and a nerve cord that runs ventrally through the thorax and abdomen. EXCRETORY SYSTEM- Malpighian tubules work with the insect hindgut to excrete nitrogenous waste products. This organ empties directly into the alimentary canal, and connects at the junction between the midgut and hindgut. CIRCULATORY SYSTEM- Tcavity that carries blood (hemolymph), called a hemocoel. (dorsal heart ® aorta ® hemocoel). Ostia (openings in the heart) close when heart contracts. When heart relaxes, the ostia open and blood is sucked into openings. The blood of insects is colorless because it lacks respiratory pigments; it functions to carry nutrients, not gases.

INSECTS pictures Referring to the vast amounts of orders under the class of Insects: Blattodea Hymenoptera Phthiraptera S iphonaptera German Cockroach Bee Stick Insect Flea

REOURCE LIST FOR INFORMATION: FOR PICTURES: animals.howstuffworks.com/insects/flea-info.htm