glossary Flashcards
what is phylum porifera?
the sponges
what is an asconoid?
the simplest form of sponge, usually tube shaped
what is a syconoid?
second simplest form of sponge, but the body wall is wiggly.
what is a leuconoid?
the most complex structure of the sponges, it has multiple chambers.
what are parazoa?
multi cellular animals with very little specialisation of cells.
what is a pinacocyte?
a type of flat cell that covers the external surface and incurrent and excurrent canals in sponges.
what are porocytes?
tubular cells which make up the pores of sponge, known as ostia.
what is a choanocyte?
a flagellated cell with a collar of protoplasm that line the internal chambers of sponges.
what are sclerocytes?
these are essential for the excretion of spicules, they are specialised cells which create the mineral structure.
what is a gemmule?
an internal bud found in sponges that is involved in asexual reproduction. it is a cluster of embryonic cells.
what does monoecious mean?
to have both male and female sexual organs in one individual.
what does diploblastic mean?
an animal that has a body wall made up of two layers, sometimes with a non cellular mesoglea between the two layers.
what is the ectodermis?
one of the three primary layers in an early embryo
what is the endodermis/gastrodermis?
an inner layer of cells that serves as a lining membrane.
what is the mesoglea?
a jelly like substance that sits between the endodermis/gastrodermis and the ectodermis/epidermis.
what is a polyp?
it is a phase in the life-cycle of the phylum cnidaria, it is a column body with a mouth at the top surrounded by tentacles.
what is a medusa?
a medusa is a free swimming sexual form of cnidaria, it typically has an umbrella shaped body and tentacles with stingers.
what is alternations of generations?
the alternation between a sexual form and a asexual phase in the life cycle of an organism.
what is dimorphism?
the representation of two distinct forms
what is polymorphism?
the occurrence of many different forms among the same members of the population.
what is a gastrozooid?
an organism with a mouth and digestive organs
what is gonozooid?
a term applied to an animal species that practises alternations of generations. its only function is to reproduce (typically)
what is meant by dactylozooid?
a polyp like form that does not have a mouth and is heavily armed with nemocytes for protection.
what is a gastrovascular cavity?
a body cavity with a highly branched canal system featuring digestive and circulatory functions.
what are cnidocytes (nemocytes)?
they are used to catch prey and for protection, they secrete toxins and poisons.
what is a nerve net?
a network of cells connected by fusion. in some invertebrates, it is only in the body wall.
what is a septa?
a wall separating two cavities.
what are hydrozoa?
small predatory animals such as jellyfish and corals. all marine.
what are hydroids?
the asexual polyp stage in the life cycle of a hydrozoa . it can also be when the polyp form is dominant over the medusa form.
what is a scyphozoa?
the true jellyfish, exclusively marine.
what are cubozoa?
commonly known a the cube jelly fish or box jelly fish.
what is the class of anthozoa?
the class that includes sea anemones and corals.
