Final Flashcards
has two embryonic cell layers; ectoderm and endoderm
diploblast
has three embryonic cell layers; ectoderm, mesoderm, and endoderm
triploblast
each of the three layers of the cells that are formed in the early embryo
germ layer
outermost layer of cell
ectoderm
innermost layer of cell
endoderm
middle layer
mesoderm
a structure containing a number of nerve cell bodies
ganglia
living and non-living things when rotated through a center of rotation by more than 0° and less than 360°, exactly match each other in orientation and shape.
radial symmetry
symmetrical halves on either side of a unique plane
bilateral symmetry
The formation in animals of a distinct anterior region (the head) where sense organs and a mouth are clustered
cephalization
an internal, usually fluid-filled body cavity that is completely or partially lined with mesoderm
coelom
A bilaterian animal that lacks an internal body cavity (coelom)
acoelomate
an animal that has a true coelom, completely lined with mesoderm
coelomate
A system of body support involving a body wall in tension surrounding a fluid or soft tissue under compression
hydrostatic skeleton
A member of a major lineage of animals that are bilaterally symmetrical at some point in their life cycle, have three embryonic germ layers, and have a coelom (or evolved from ancestors that had a coelom). Includes all protostomes and deuterostomes
Bilateria
A major lineage of bilaterian animals including arthropods, mollusks, and annelids; sister group to deuterostomes
protostome
A major lineage of bilaterian animals that includes echinoderms and chordates; named for the embryonic development of the anus before the mouth; sister group to protostomes
deuterostome
The process of coordinated cell-shaped changes and movements, including the movement of some cells from the outer surface of the embryo to the interior that results in the formation of the three germ layers and establishes the axes of the embryo
gastrulation
A major lineage of protostomes that grow by shedding their external skeletons (molting) and expanding their bodies; includes arthropods, nematodes, and other groups
Ecdysozoa
A major lineage of protostomes that grow by extending their skeletons rather than by molting; many phyla have a specialized feeding structure (lophophore) and/or ciliated larvae (trochophore); includes rotifers, flatworms, segmented worms, and mollusks
Lophotrochozoa
Division of the body or a part of it into a series of similar structures; exemplified by the body segments of insects, annelid worms, and vertebrates
segmentation
One of the three major chordate lineages, comprising animals with a dorsal column of cartilaginous or bony structures (vertebrae) and a skull enclosing the brain; includes fishes, amphibians, mammals, and reptiles (including birds)
vertebrates
A non-monophyletic group composed of animals without a backbone; includes about 95 percent of all animal species
invertebrates
a rasping feeding appendage in mollusks such as gastropods
radula
bony and/or cartilaginous structures within the body that provide support
endoskeleton
hard covering secreted on the outside of the body, used for body support, protection, and muscle attachment
exoskeleton
fertilization occurs inside the female
internal fertilization
fertilization occurs outside the female
external fertilization
in animals, depositing fertilized eggs outside the body, where they develop and hatch
oviparous
in animals, producing live young that develop within and are nourished by the body of the female parent, typically via a placenta, before birth
viviparous
in animals, producing eggs that are retained inside the body until they are ready to hatch and released via live birth
ovoviviparous
an immature form of an animal species in which the immature and adult stages have different body forms
larva (plural: larvae)
nymph
In insects undergoing complete metamorphosis, the life stage during which the juvenile form metamorphoses into the adult form
pupa
A type of metamorphosis in which the animal completely changes its form; includes a distinct larval stage
complete metamorphosis
A type of metamorphosis in which the animal increases in size from one stage to the next, but typically does not dramatically change its body form
incomplete metamorphosis
the immotile (sessile) stage in the life cycle of some cnidarians (e.g., sea anemones)
polyp
the free-floating stage in the life cycle of some cnidarians (e.g., jellyfish)
medusa
a phylum of aquatic invertebrate animals that comprises the sponges.
Porifera/sponges
a phylum of aquatic invertebrate animals that comprises the coelenterates
Cnidaria
a sedentary coelenterate of warm and tropical seas, with a calcareous, horny, or soft skeleton. Most corals are colonial and many rely on the presence of green algae in their tissues to obtain energy from sunlight.
corals
a plant of the buttercup family, typically bearing brightly colored flowers. Anemones are widely distributed in the wild, and several kinds are popular garden plants.
anemones
a coelenterate of an order which includes the hydras. They are distinguished by the dominance of the polyp phase.
hyroids
A gelatinous material, containing scattered ectodermal cells, that is located between the ectoderm and endoderm of cnidarians (e.g., jellyfish, corals, and anemones).
mesoglea
A specialized stinging cell found in cnidarians (e.g., jellyfish, corals, and anemones).
cnidocyte
a small phylum of aquatic invertebrates that comprises the comb jellies.
Ctenophora/comb
simultaneous hermaphrodites, but have no gonads and no ducts associated with the female reproductive system
Acoelomorpha
A specialized feeding structure found in some lophotrochozoans and used in suspension (filter) feeding
lophophore
A larva with a ring of cilia around its middle that is found in some lophotrochozoans
trochophore larva
A protective coating secreted by the outermost layer of cells of an animal or a plant; often functions to reduce evaporative water loss
cuticle
A method of body growth, characteristic of ecdysozoans, that involves the shedding of an external protective cuticle (exoskeleton in arthropods), expansion of the soft body, and growth of a new external cuticle
molting
Prominent body regions in arthropods, such as the head, thorax, and abdomen in insects
tagma (plural tagmata)
The anteriormost region of many bilaterian animals, usually containing specialized sensory structures and the brain
head
A region of the body; in arthropods, one of the three prominent body regions (tagmata), located between the head and abdomen; in vertebrates, including humans, the chest
thorax
A region of the body; in arthropods, one of the three prominent body regions (tagmata), located posterior to the thorax
abdomen
In most of the leg, the exoskeleton is hard, but at the joints it is softer and bendable, allowing movement in the same way that a suit of armor does; most arthropods have them
jointed limb
A structural polysaccharide composed of N-acetyl-glucosamine (NAG) monomers joined end to end by beta-1,4-glycoside linkages. Found in the cell walls of fungi and many algae, and in external skeletons of insects and crustaceans
chitin
A body cavity, present in arthropods and some mollusks, containing a pool of circulatory fluid (hemolymph) bathing the internal organs; not lined with mesodermally derived tissue
hemocoel
One of the three main parts of the mollusk body; a muscular appendage, used for movements such as crawling and/or burrowing into sediment
foot
One of the three main parts of the mollusk body; contains most of the internal organs and external gill
visceral mass
One of the three main parts of the mollusk body; the thick outer tissue that protects the visceral mass and may secrete a calcium carbonate shell
mantle
functions as a respiratory cavity
mantle cavity
an elongated sucking mouthpart that is typically tubular and flexible.
proboscis
A tubelike appendage of many mollusks, often used for feeding or propulsion
siphon
propulsion by the backward ejection of a high-speed jet of gas or liquid.
jet propulsion
A form of asexual reproduction in which offspring develop from unfertilized eggs
parthenogenesis
a small phylum of minute multicellular aquatic animals which have a characteristic wheel-like ciliated organ used in swimming and feeding.
Rotifera (rotifers)
a part of the body resembling or likened to a crown
corona
development without a metamorphosis
direct development
Distinguished by a broad, flat, unsegmented body that lacks a coelom. Flatworms belong to the lophotrochozoan branch of the protostome animals
Platyhelminthes
free-living flatworms
Turbellaria
a class of parasitic flatworms that comprises the tapeworms.
Cestoda
parasitic flatworms including flukes
Trematoda
the parasite becomes an adult and reproduces sexually
definitive host
the organism in which the parasite primarily grows to the point of sexual maturity
intermediate host
Distinguished by a segmented body and a coelom that functions as a hydrostatic skeleton; belong to lophotrochozoan branch of protostomes
Annelida (segmented worms)
a class of marine annelid worms which comprises the bristle worms.
Polychaeta
Bristle-like extensions found in some annelids
chaeta
appendages found in some annelids from which bristle-like structures (chaetae) extend
parapodium
a class of annelid worms which includes the earthworms. They have simple setae projecting from each segment and a small head lacking sensory appendages
Oligochaeta
class comprising leeches
Hirudinea
A lineage of protostomes with a body plan based on a muscular foot, visceral mass, and mantle, includes chitons, clams, oysters, snails, slugs, squid, octopuses, and other
Mollusca/mollusks