Unit 6 - Arthropoda

mandibles

One of a pair of jaw-like feeding appendages found in myriapods, hexapods, and crustaceans.

book lungs

Organs of gas exchange in spiders, consisting of stacked plates contained in an internal chamber.

Arthropoda

Phylum that have jointed appendages, an exoskeleton, bilateral symmetry, and reproduce sexually; insects, arachnids, millipedes and cenitpedes, and crustaceans

chitin

a carbohydrate that forms part of the exoskeleton of arthropods and other organisms, such as insects, crustaceans, fungi, and some algae

social arthropods

live in large groups with typically one reproductive queen, haploid males and female workers with different jobs ex) bees, wasps, termites, ants

segments and jointed appendages are better for

locomotion

Arthropods are protostomes

mouth forms first in embryonic development

chelipods

pair of large grasping claws in crustaceans

chelicera

pair of mouthparts in chelicerates that contain fangs and are used to stab and paralyze prey in chelicerata (arachnids)

spiracles

small opening located along the side of the body through which air enters and leaves the body of many terrestrial arthropods

swimmerets

small paired appendages located on the ventral surface of the abdomen of crustaceans used for swimming or reproduction

Arthropods account for ____% of all species on Earth

75

Insects make up _____% of Arthropods

90

compound eyes

eyes that contain many lenses and are especially keen at sensing movement

arachnids

A member of a major arthropod group, Chelicerata, that includes spiders, scorpions, ticks, and mites. All members have four pairs of walking legs, two body sections and no antennae.

malpighian tubules

An excretory organ that is unique to insects, empties into digestive tract and removes nitrogenous wastes from the hemolymph, also plays a role in osmoregulation.

thorax

An insect's midsection, to which its wings and legs are attached.

complete metamorphosis

Growth to the adult stage from larval stage (often many) to a transformative pupa stage and finally into the adult form: egg --> larva --> pupa --> adult example: butterfly, fly, beetle

incomplete metamorphosis

Growth to the adult stage without a pupa phase (intermediate phase is called a nymph): egg --> nymph --> adult example: dragonfly, spider, lobster

Viviparous

Internally fertilized eggs develop inside the female body and derive nutrition from her directly. Female gives birth to live young. Ex) scorpions, humans, cows

Oviparous

Internally fertilized eggs develop into eggs that are laid and hatch outside the mother's body

Ovoviviparous

Internally fertilized eggs develop within the mother's body but derive nutrition from the yolk of the egg (not her body), hatch inside and are born alive

antennae

Sensory structures that are able to detect air movement, vibrations, and smells

Exoskeleton in crustaceans reinforced with

calcium

Disadvantage of exoskeleton

can't grow, must be shed

harm from arthropods

disease, bites, toxins, destroy crops

nervous system

dorsal brain at the front of the organism, connected to nerve ring around the digestive system with a ventral nerve cord

Disadvantage of ecdysis

exoskeleton is soft after making the organism vulnerable to predation

benefits to humans of arthropods

food source, pollination, production of honey, population control of other organisms

Podos (Greek)

foot

Arthropods are coelomates

have a body cavity

Arthron (Greek)

jointed

ecdysis

periodic shedding of the cuticle in arthropods or the outer skin in reptiles

Exoskeleton is always made of

protein and chitin

Advantage of exoskeleton

provides support and protection from water loss

cephalothorax

region of a crustacean and chelicerata formed by the fusion of the head with the thorax

jointed appendages

structures such as a legs, wings, or antennae that extend from the body wall of an arthropod and enable them to move and grasp objects

Chelicerata

sub-phylum of arthropods that includes spiders, scorpions, ticks, and horseshoe crabs

Crustacea

subphylum of arthropoda; crabs, lobsters, crayfish, and shrimp

Myriapoda

subphylum of arthropoda; many feet; millipedes and centipedes

Exoskeleton

supportive, non-living structure on the outside of the organism

abdomen

the hind section of an arthropods body that contains its reproductive organs and part of its digestive tract

tracheal tubes (tracheoles)

tiny tubes in insect body that deliver oxygen directly to metabolizing tissues

spinnerets

tubelike structures in a spider's abdomen that the spider uses to make silk threads