Arthropods Flashcards
Arthropod key characteristics
- segmented body
- exoskeleton of polysaccharide chitin and CaCO3
- jointed appendages
independent origin hypothesis
Wings arose as outgrowths from the thorax independent from the legs
Gill co-option hypothesis
Wings arose from gill-like projections on the branched legs of a wingless ancestor
coelom type of arthropods
hemocoeloms
what kind of circulatory system do arthropods have
open
what were the first animals to fly?
insects
developmental genetics proved that what kind of wing hypothesis was true?
Results strongly support the gill co-option hypothesis
two types of insect metamorphosis
- Hemimetabolous metamorphosis (incomplete metamorphosis)
- Holometabolous metamorphosis (complete
metamorphosis)
Hemimetabolous metamorphosis (incomplete metamorphosis)
- Form of direct development
- Juveniles called nymphs look like smaller versions of the adult
Holometabolous metamorphosis (complete
metamorphosis)
- There is a distinct larval stage
- Larvae and adults often live in different habitats and feed on
different foods - In holometabolous metamorphosis, larvae stop feeding and moving
and secrete a protective case, becoming a pupa - During pupation, the pupa’s body is completely remodeled into a new, adult
form
why metamorphose?
feeding efficiency- If adults and juveniles feed on different resources in different ways, they do not compete with each other for resources
reproduction of anthropoda
diecious (2 sexes)
internal fertilization
digestive system of anthropods
cirulatory system of anthropods
open
nervous system of anthropods
movement of anthropods
appendages
wings sometimes
anthropoda role in ecosystem
