Chapter 8 Flashcards
Four Shared Characteristics of Animals
Animals are multicellular
2) Animal cells are eukaryotic & lack cell walls
3) Animals cannot produce their own food
4) Animals can actively move (at some point in their life history)
Invertebrates
animals that lack a backbone
Vertebrates
animals that have a backbone
Sponges (Phylum Porifera)
Sponges
simple, asymmetrical, sessile animals
Sessile
Sponges
permanently attached to a solid surface
Ostia
Sponges
holes in the body of sponges through which water enters
Spongocoel
Sponges
cavity in the body of a sponge
Osculum
Sponges
opening through which a sponge expels water
Tissues
Sponges
groups of specialized cells that preform a specific function (lacking in sponges)
Collar Cells (Choanocytes)
Sponges
flagellated cells in a sponge that circulates water and traps food
Pinacocytes
Sponges
Cells that make up the outer covering of a sponge and line the internal chambers not lined by choanocytes
Archaeocytes
Sponges
cells that form any of the cell types in the sponge’s body
Spicules
Sponges
structures that support a sponge’s body; made of CaCO3, silica, or spongin
Spongin
Sponges
a protein that makes up flexible spicules
Sponge Body Forms
Sponges
size limited by ability to circulate water and body form
Asconoid
Sponges
type of sponge body that lacks invagination; simple, tubular, small, found in clusters
Syconoid
Sponges
type of sponge body with a single spongocoel containing many invaginations; pockets lined with choanocytes
Leuconoid
Sponges
type of sponge body with multiple spongocoels and chambers leading to them; chambers lined with choanocytes, most complex / largest sponges
Suspension Feeder
an organism that feeds on food suspended in the water (20% of feeding via phagocytosis)
Filter Feeders
Sponges
an organism that filters its food from the water (80% of feeding; trapped by collar or on choanocyte cell surface)
Budding
Sponges
a type of asexual reproduction in which a group of cells on the surface of the parent develop into a new individual
Hermaphrodites
Sponges
are animals that can produce both male and female gametes
Sperm – formed from modified choanocytes
Eggs – usually develop from archaeocytes
Stimulus to produce gametes is caused by changes in water temperature and
Photoperiod
Sponges
the relative amount of light and darkness in a 24-hour period
Sponge Competition
Sponges
Compete with corals and bryozoans; make chemicals that kill corals
Sponge Predators
Sponges
silica spicules inhibit grazing; fed on by a few fish and molluscs and hawksbill sea turtles
Sponge Symbiosis
Sponges
symbiotic bacteria, cyanobacteria, shrimp, and fishes
Cnidarian
Cnidarians
an animal that belongs to Phylum Cnidaria; named for Cnidocyte
Cnidocyte
Cnidarians
a stinging cell found in all cnidarians
Radial Symmetry
Cnidarians
the organization of body parts around a central axis
Polyp
Cnidarians
the generally benthic form of cnidarian characterized by a cylindrical body with an opening at one end, usually surrounded by tentacles
Medusa
Cnidarians
the free-floating form of a cnidarian that resembles and umbrella
Epidermis
Cnidarians
an outer layer of cells