Diversity of Eukaryotic Life: Basal Animals (Phyla Porifera, Placozoa, Cnidaria, Ctenohora

porifera

________ are early diverging lineages in the kingdom Animalia

metazoans

animals are ______ (eukaryotic multicellular animals)

placozoa

• early divergence among the metazoa

• simple multicellular animals

porifera

• no symmetry

• mostly marine

• different cell types

• have collagen (spongin)

• no hox genes

• sessile

• cell-to-cell transfer

• gas exchange via diffusion

• intracellular digestion )no gut)

spongin

type of collagen in Porifera

Paleozoic

sponges have a long evolutionary history with fossils dating to early ________

totipotent cells

cells squeeze out of a sponge can reaggregate and form a new sponge organism by _______ ______ can become any cell type

choanocytes

produces currents that draw water and food from the water column through pores in outer epidermal cells (Ostia)

spongocoel

center cavity of sponge

osculum

opening it flows out to (unidirectional)

feeding choanocytes

the internal canals/chambers or rarely the spongocoel and use a collar of microvilli to trap and phagocytize food particles

mesohyl

gelatinous proteinaceous acellular matric beneath the outer pinacoderm in which amoebocutes and supporting elements such as stiff spicules and flexible fibers of spongin are embedded.

amoebocytes

totipotent cells can form all types of cells move throughout the meshyl

spicules

used for support and defense

Silica

sponges produce _____ spicules “glass sponges”

calcareous

some sponges produce _______ spicules “cancerous sponges”

spongin

some sponges produce _____ fibers - modified collagen - bath sponges

monoecious

sperm and egg on one individual

dioecious

separate individuals with sperm and egg

broadcast spawning

when stimulus is right some choanocytes in a sponge become sperm or eggs are released through the osculum into the mater in MASS

choanocyte

maintains unidirectional flow and captures gametes

amoeboid

sperm captured by choaocute which becomes ________ and travels through the mesophyll to fertilize egg

water filtration and nutrient recycling

what are sponges important for

radial

phylum cnidaria exhibit mostly _______ symmetry

diploblastic

embryologic tissues: ectoderm & endoderm

blastula

the zygote undergoes cleavage multiple rounds of mitosis occurs after fertilization transforming the single cell zygote into a hollow, multicellular ________.

gastrulation

during ________ some of the outer embryonic cells of blastula are pushed inward (invagination) embryonic tissues (germ layers) are formed as cells migrate and reorganize to form the endoderm and the ectoderm

blastopore

_______ forms mouth and anuss

epidermis

formed from ectoderm

gastrodermis

formed from endoderm

statocyst

gravity sensing structure

ocelli

light sensing structure

nerve net

nervers diffused all over body - decentralized. - diffuse networked of interconnected neurons

simple diffusion

circulation/transport & osmoregulation/excretory process is through

extracellular, intracellular

captures prey with tentacles __________ (in GVC), and_________ digestion (gastrodermis

polyp

cylindrical usually sessile but some can move solitary or colonial tentacles surround a mouth/anus that face upward

medusa

umbrella shaped or bell floats or swims tentacles surround a mouth/anus that faces downward

gomad

gametes that are in medusa form and are used for reproduction

cnidocyte

_______ cells in tentacles used in prey capture and for defense

cnidae

cnidocytes contain organelles called ______.

nematocysts

most common cnidate are ______ that eject barbed stinging toxic harpoon like threads

cnidocyte

_______ is triggered by physical contact (cnidocil)

operculum

________ “trap door” pops open and the coiled up toxic, barbed nematocyst is ejected

longitudinal microfilaments

outer epidermis has muscle cells with _______ __________

circular microfilaments

inner gastrodermis has muscle cells with ________ __________.

stem cells

the muscles/tissies embedded with ____ _____

epidermis

provides support and protection

gastrodermis

derived from endoderm and has silica and draws things in with it

nerve net

_____ ____ which are nerve cells found in the epidermis and gastrodermis (no central nervous system)

enzymes

cells secrete digestive ________ secreted into GVC t carry out extracellular digestion = food broken down into smaller particles.

GVC

cavity where digestion occurs

hydrostatic

_______— skeleton consists of the fluid filled GVC that provides support and allows for movement through muscle contractions that change the pressure within the cavity