Bio 2.2 Lab 1

Choanocytes

flagelleted cells that create incurrent of water and trap food particles.

Pinacocytes

tough cells that form a protective covering on the sponge surface and line the canals

Ameobocytes

move among choanocytes and digest large food particles. Give nutrient to themselves but also other cells.

Mesohyl

gellatinous extracellular matrix within spongeSclerocy

Sclerocytes

in the mesohyl and secrete spicules. In Demospongiae and Hexactinellida spicules are silica and in Calcarea spicules are calcium carbonate

Spongocytes

secrete form of collegan that polymerizes into spongin

Spongin

tough but flexible protein that provides structural support in some sponges in the Demospongiae class

Porocytes

tubular cells that make up the Ostia

Ostia

pores on sides of sponge where water flows in

Osculum

where water exits the sponge

Archaeocytes

can produce any of the sponge cell types

Asexual reproduction

gemmulation, fragments of the sponge break off and land in suitble enviornment to attach and grow

Spicules

form a skeleton-like framework for the organism

Taxonomy

Classification and naming of organisms

Linnean Taxonomy

Carolus Linnaeus came up with taxonomic system most commonly used today, categories were based on morphology.

Hierarchy of taxonomic order

Do Kings Play Chess On Fine Green Sand?

Cladistics

Using evolutionary relationships to define taxonomic groups

Clade

An ancestor and all its descendants. A monophyletic grouping

Paraphyletic

Ancestor without all of its descendants

Polyphyletic

Some taxa, most common ancestor not included

Homologous traits

Used to define clades. Features derived from common ancestor

Homoplasy

Independent evolution of similar traits

Taxa/taxon

Names of organisms and clades they are in

Node

Place where branches divide, shows common ancestor to everyone past the node

Synapomorphy

Trait that is unique to a clade

pleisiomorphy

Ancestral trait may or may not be present in all members of a clade, not used to define clades

Class Anthozoa

Polyps only

Ex: sea pens, sea pansies, most coral, sea anemones