Taxonomy Flashcards
Animals can be categorized according to the absence of different types of tissues (the Parazoa, or * ) and the presence of tissues (Eumetazoa, or all other animals).
sponges
the *, or animals without a backbone, a category that makes up more than 95% of all animal species
invertebrates
The Parazoa consist of one phylum, * (from the Latin, meaning pore bearers), whose members are commonly referred to as sponges.
Porifera
lack true tissues—groups of cells that have a similar structure and function. However, sponges are multicellular and possess several types of cells that perform different functions.
Sponges
members of Porifera are commonly
referred to as
sponges
The Radiata consists of two closely related phyla: the * (from the Greek knide, meaning nettle, and aria, meaning related to; and the * (from the Greek ktenos, meaning comb, and phora, meaning Members of the Radiata phyla, or radiates, are mostly found in marine environments, although a few, such as hydra, are freshwater species .
Cnidaria , Ctenophores
freshwater
species
hydra
hydra, jellyfish, box
jellies, sea anemones, and
corals, and the
Cnidaria
comb jellies
Ctenophora
Nearly all ctenophores exhibit * , a phenomenon that
results from chemical reactions that give off light rather than heat.
bioluminescence
- , or flatworms, were among the first animals to
develop an active predatory lifestyle. *, and indeed
most animals, are bilaterally symmetrical, with a head bearing sensory appendages, a feature called cephalization
Platyhelminthes (from the Greek platy, meaning flat, and helminth,
meaning worm)
Members of the phylum * (from the Latin rota, meaning wheel, and fera, meaning to bear) get their name from their ciliated crown, or corona, which, when beating, looks similar to a rotating wheel . Most rotifers are microscopic animals, usually less than 1 mm long, and some have beautiful colors. There are about 2,000 species of *, most of which inhabit fresh water, with a few marine and terrestrial species. Most often they are bottom-dwelling organisms, living on a pond floor or along lakeside vegetation.
Rotifera
* constitute a very large phylum, with over 100,000 living species, including organisms as diverse as snails, clams, octopuses, and chitons. They are an ancient group, as evidenced by the classification of about 35,000 fossil species. Many serve as sources of food, including scallops, oysters, clams, and squids.
Mollusks (from the Latin mollis,
meaning soft)
snails, clams, octopuses, and
chitons
Mollusks
* are a large phylum with about 15,000 described species. Its members include free-ranging marine worms, tube worms, the familiar earthworm, and leeches. derived from the Latin annulus, meaning little ring. Each ring is a distinct segment of the annelid’s body, and each one is separated from the one in front of it and the one behind it by septa.
Annelida
free-ranging marine worms, tube worms, the familiar
earthworm, and leeches
Annelida
also called roundworms, are small, thin worms that range from less than 1 mm to about 5 cm
nematodes (from the Greek nematos, meaning thread)
About three-quarters of all described living species present on Earth are *
The arthropods (from the Greek arthron, meaning joint, and podos, meaning foot)
The body of a typical * is covered by a hard cuticle, an exoskeleton (external skeleton), made of layers of chitin and protein. * are segmented, and many of the segments bear jointed appendages
arthropod
(class * ) have two pairs of legs per segment, as their class name denotes (from the Latin diplo, meaning two, and podos, meaning feet), not 1,000 legs, as their common name suggests 8toxic
Diplopoda
