Chapter 33 Flashcards
Invertebrates
Animals lacking a backbone
Invertebrates account for more than _____ of know animal species
95%
Example of Porifera
Sponge
Example of Acoela
flatworms
Example of Ctenophora
Comb Jelly
Example of Cnidaria
Jelly
Example of Placozoa
Placozoan
Animals in the phylum Porifera are known informally as ________
sponges
Filter feeders
animals that capture their food particles that are suspended in the water that pass through their body
T/F: Sponges lack true tissues and organs
True
Cnidarians have diversified into a wide range of both ______ and ______ forms including jellies, corals, and hydras
Sessile; motile
The gastrovascular cavity
the main part in the basic body plan of a cnidarian; a sac with a central digestive compartment
T/F: Cnidarians have two holes: a mouth and an anus
False; they have one hole that functions as both
Two variations of the Cnidarian body plan
A polyp or medusa
Polyp
sessile; adheres to the substrate by the aboral end of its body
Medusa
has a bell-shaped body with its mouth on the underside
The clade Bilateral contains ___________, __________, and ____________
Lophotrochozoa; Ecdysozoa; Deuterostomia
Flatworm phylum
Platyhelminthes
Planarians
the best-known flatworms
Planarians live in __________ and prey on ____________
fresh water; smaller animals
T/F: Planarians have eyes
False; they have light-sensitive eyespots
Hermaphrodites
organisms that can reproduce sexually, or asexually through fission
Mulluscs’ phylum and what it includes
Mollusca; snails, slugs, oysters, clams, octopuses, and squids
The three main parts of all molluscs’ body plan
1) Muscular foot
2) Visceral mass
3) Mantle
Four major classes of molluscs
1) Polyplacophora (chitons)
2) Gastropoda (snails and slugs)
3) Bivalvia (clams, oysters, and other bivalves)
4) Cephalopoda (squids, octopuses, and cuttlefish)
Annelids
Coelomates with bodies composed of a series of fused rings
Leeches secrete ________ to prevent blood from coagulating
hirudin
Cuticle
the tough coat covering Ecdysozoans
The two largest phyla of Exdysozoans
1) nematodes (roundworms)
2) arthropods
Arthropod body plan
consists of a segmented body, hard exoskeleton, and jointed appendages (dates back to the Cambrian explosion)
Open circulatory system
Hemolymph is circulated into the spaces surrounding the tissue and organs rather than through blood vessels
Book lungs
found in spired; allowed for gas exchange
Most modern chelicerates are ________, which include…
arachnids; …spiders, scorpions, ticks, and mites
Myriapods include __________ and ___________
millipedes; centipedes
T/F: Most living myriapods are terrestrial
False; All are terrestrial
Echinoderms include…
sea stars and sea urchins
Chordates include…
vertebrates
Echinoderm phylum
Echinodermata
Chordates phylum
Chordata
Echinoderms and chordates constitute the clade _____________
Deuterostomia
Deuterostomes share the developmental traits…
Radial cleavage and the formation of the anus from the blastopore
Echinoderms
slow-moving or sessile marine animals such as sea stars
water vascular system
Shared by echinoderms; a network of hydraulic canals branching into tube feet that function in locomotion and feeding
