mnmknk Flashcards
define mesoderm
the middle layer of an embryo in early development, between the endoderm and ectoderm.
define ectoderm
the outermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the epidermis and nerve tissue.
define endoderm
the innermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the lining of the gut and associated structures.
define anterior
nearer the front, especially situated in the front of the body or nearer to the head.
define posterior
further back in position; of or nearer the rear or hind end, especially of the body or a part of it.
define dorsal
of, on, or relating to the upper side or back of an animal, plant, or organ.
define ventral
of, on, or relating to the underside of an animal or plant; abdominal.
define mesoglea
: a gelatinous substance between the endoderm and ectoderm of sponges or cnidarians.
define acoelomte
one belonging to the group comprising the flatworms and nemerteans
define nerve net
Nerve net, primitive nerve arrangement forming the entire nervous system of many cnidarians and a part of more advanced nervous systems
define planula
Planula, plural planulae, free-swimming or crawling larval type common in many species of the phylum Cnidaria (e.g., jellyfish, corals, and sea anemones).
define ephyra
: a free-swimming larva of a scyphozoan jellyfish formed by transverse fission of a scyphistoma and growing into a medusa — compare strobila.
define collar cell (choanocyte)
Their flagella beat to create the active pumping of water through the sponge, while the collars of the choanocytes are the primary areas that nutrients are absorbed into the sponge.
define amoebocyte
any cell having properties similar to an amoeba, such as shape, mobility, and ability to engulf particles.
define proglottid
: a segment of a tapeworm containing both male and female reproductive organs.
