{ Characteristics }
Arthropods have a segmented body, tough exeskeleton, and jointed appendages.
Reproduction
Arthropods reproduce sexually.
Terrestrial arthropods have internal fertilization, whereas aquatic arthropods may have internal or external fertilization. There are two different metamorphoses arthropods can undergo. When an egg hatches into a mature adult, no metamorphosis occurs. When an egg develops into a nymph before the adult stage, the arthropod undergoes incomplete metamorphosis. When an egg develops into a larva, pupa, then adult, the arthropod undergoes complete metamorphosis.
Examples of Arthropods
There are three groups of arthropods. The subphylum Crustacea contains crabs, shrimps, lobsters, crayfishes, and barnacles. They are primarily aquatic, have two pairs of antennae, two or three body sections, and chewing mouthparts called mandibles. The subphylum Chelicerata includes horseshoe crabs, spiders, ticks, and scorpions. They have mouthparts called chelicerae and two body sections, and nearly all have four pairs of walking legs. The subphylum Uniramia contains centipedes, millipedes, and insects. They have jaws, one pair of antennae, and unbranched appendages.
Vocabulary
exoskeleton - external skeleton; tough external covering that protects and supports the body of many invertebrates
chitin - complex carbohydrate that makes up the external skeletons of arthropods
appendage - structure, such as leg or antenna that extends from the body wall
tracheal tube - one of many branching, air-filled tubes that extend throughout the bodies of many terrestrial arthropods
spiracle - small opening located along the side of the body through which air enters and leaves the body of many terrestrial arthropods
book lung - organ that has layers of respiratory tissue stacked like the pages of a book; used by some terrestrial arthropods for the exchange of gases
Malpighian tubule - saclike organ in most terrestrial arthropods that extracts wastes from the blood, adding them to feces that move through the gut
molting - process in which an arthropod sheds its exoskeleton and manufactures a larger one to take its place
cephalothorax - region of a crustacean formed by the fusion of the head with the thorax
thorax - body part of a crustacean that lies just behind the head and houses most of the internal organs
abdomen - posterior part of an arthropod’s body
carapace - the part of the exoskeleton that covers the cephalothorax
mandible - mouthpart adapted for biting and grinding food
cheliped - on of the first pair of legs of decapods
swimmeret - flipperlike appendages used by decapods for swimming
chelicera - pair of mouthparts in chelicerates that contain fangs and are used to stab and paralyze prey
pendipalp - pair of mouthparts in chelicerates that are usually modified to grab prey
spinneret - organ in spiders that contains silk glands
incomplete metamorphosis - type of insect development characterized by a similar appearance throughout all stages of the life cycle
nymph - immature form that lacks functional sex organs and other adult structures
complete metamorphosis - type of insect development in which the larvae look and act nothing like their parents and also feed in completely different ways
pupa - stage of metamorphosis in which an insect changes from a larva into an adult
pheromone - specific chemical messenger that affects the behavior or development of other individuals of the same species
society - group of closely related animals of the same species that work together for the benefit of the group
caste - group of individual insects specialized to perform particular tasks, or roles
Works Cited
http://www.valdosta.edu/~sljennin/060515_dragonfly_hmed_9a.widec.jpg
http://images.cdn.fotopedia.com/flickr-3494553666-image.jpg
http://www.occc.edu/trandall/biologylabs/Images/Arthopods/LargeRealBug.jpg
No comments:
Post a Comment