Animal diversity Terms Flashcards
Diplontic life cycle
refers to the life cycle of organisms, which is dominated by the diploid stage.
Asymmetry
is the absence of, or a violation of, symmetry
Radial symmetry
symmetry in which the body is shaped like a pie or barrel (lacks a left and right side) and can be divided into mirror imaged haves by any plane through its central axis
Oral–Aboral axis
cnidarians have this
single body axis- have their mouth on the oral surface and their opposite side is the aboral surface
Bilateral symmetry
A central longitudinal plane divides the body into 2 equal but opposite halves
Cephalization
evolutionary trend toward the concentration of sensory equipment at the anterior end of the body)
Anterior
front
posterior
back
dorsal
top
ventral
bottom
Diploblastic
having only 2 germ layers
germ layers means tissues
Triploblastic
Having 3 germ layers: the endoderm mesoderm and ectoderm; most eumetazoans are this
Endoderm
the innermost germ layer, lines the pouch that forms during gastrulation (the archenteron) and gives rise to the lining of the digestive tract and organs such as liver lungs of vertebrates
Mesoderm
The middle primary germ layer in a triploblastic animal(bilaterally symmetrical animals) embryo that forms after gastrulation which fills the space between the ecto and endoderm that develops into the notochord the lining of the coelom muscles skeleton gonads kidneys and most of circulatory system (most organs between digestive tract and outer covering of the animal)
Ectoderm
the outermost of the 3 primary germ layers; covering the surface of the embryo gives rise to outer covering of animal and in some phlya the central nervous system, inner ear and lens of the eye
Coelom
true body cavity- found in large animals(called coelomates) - a body cavity between the digestive tract (derived from the endoderm) and the outer body wall (ectoderm); Forms from tissue derived from the mesoderm
Acoelomate
some triploblastic animals are compact and lack a body cavity
Small and or flat animals that don’t require internal transport and circulation system instead rely on diffusion
archenteron just vanishes
Pseudocoelomate
Animals with only a hemocoel
(Eu)coelomate
any animal that has a true coelom (fluid filled body cavity) which surrounds the gut and is lined on both sides by mesoderm.
True Tissue
eumetazoans
Segmentation
is the division of some animal and plant body plans into a series of repetitive segments
Determinate development
A type of embryonic development in protostomes that rigidly casts(determines) the developmental fate of each embryonic cell very early
Deuterostome
deuteros= second)
in animals a developmental mode distinguished by the development of the anus from the blastopore; also characterized by radial and indeterminate cleavage and by the body cavity forming as out pockets of mesodermal tissue
Schizocoely
the process by which protostome animal embryos develop; it occurs when a coelom (body cavity) is formed by splitting the mesodermal embryonic tissue
Indeterminate development
a type of embryonic development in deuterostomes in which each cell produced by early cleavage divisions keeps the ability to develop into a complete embryo
Invertebrates
an animal without a backbone; make up 95% of animal species
Enterocoely
the process by which deuterostome animal embryos develop; the coelom forms from pouches “pinched” off of the digestive tract
Mesohyl
gelatinous region that separates the 2 layers of the sponge body
Choanoderm
a type of cell layer composed of flagellated collar cells, or choanocytes, found in sponges.
Pincaocytes
one of the flat cells covering the external surface and lining the incurrent and excurrent canals of sponges
are part of the epithelium in sponges. They play a roll in movement (contracting and stretching), cell adhesion, signaling, phagocytosis, and polarity
are filled with mesohyl
Spicules
tough sharp skeletal fibers made of calcium carbonate or silica
found in sponges (exoskeleton)
made by amoebocytes
Totipotent
can differentiate into other types of sponge cells, like stem cells- can transform into any cell type that is needed by body
Pluripotent
a cell that can give rise to many but not all parts of an organism
Multipotent
have the ability to form multiple types of cells
Gastrovascular cavity
a central cavity with a single opening in the body of certain animals, including cnidarians that function in digestion and distribution of nutrients
Epidermis
Outer cell layer of body wall of cnidarians; derived from ectoderm
Mesoglea
gelatinous layer sandwiched between the epidermis and gastrodermis found in cnidarians
Polyp
cylindrical forms that adhere to the substrate by the aboral end of their body( the end opposite the mouth) and extend their tentacles waiting for prey, sessile variant of cnidarian body plan
Medusa
a flattened mouth down version of the polyp
Cnidocyte
cells unique to cnidarians; contain a capsule like organelle housing a coiled thread that when discharges explodes outward and that function in defense and prey capture
Super organism
is a group of synergetically interacting organisms of the same species.
Blastopore
in a gastrula the opening of the archenteron that typically develops into the anus in deuterostomes and mouth in protostomes, (the indentation that during gastrulation leads to the formation of the archenteron)
Pentaradial symmetry
is a form of radial symmetry where body parts are organized around anoral or aboral axis in sets of five. Pentaradial symmetry allows sedentary animals to have sensory, feeding, and other structures evenly apportioned around the body’s axis.
ex- echinoderms
Water vascular system
a network of hydraulic canals unique to echinoderms that branches into extensions called tube feet
Notochord
A longitudinal flexible rod made of tightly packed mesoderm cells that runs along the anterior posterior axis of chordate in the dorsal part of the body
Pharyngeal gill arches/slits
in chordate embryos one of the slits that form from pharyngeal clefts and communicate to the outside later developing into gill slits in many vertebrates
Post-anal tail
Have tail that extend posterior to the anus, contains skeletal elements and muscles helps propel many aquatic species
Dorsal, hollow nerve cord
develops from a plate of ectoderm that rolls into a tube located dorsal to the notochord; is unique to chordates
Nerve cord of the embryo develops into the central nervous system; brain spinal cords
Jaws
gnathostomes
Mammary gland
made up of connective tissue, fat, and tissue that contains the glands that can make milk
Continuous growth
Lophotrochozoa exhibit this type of growth
Lophophore
in some lophotrochozoan animals inlcuding brachipods a crown of ciliated tentacles that function in feeding