Lab 6: invertebrates I Flashcards
what is an animal
living organism that feeds on organic matter, with specialized sense organs, a nervous system, and the ability to respond to stimuli
animals form what monophyletic clade
metazoans
what is the basal taxon on the animal tree of life
sponges (phylum porifera) - do not form true tissues
what is the name of a monophyletic clade that posesses true tissues
eumetazoans
what is a tissue
group of cells with a similar structure and work together
what is an organ
collection of tissues that form a unit of specialized funciton
what is an organ system
group of organs working together to perform a complex function
what is an organism
living being with an organized structure, can repsond to stimuli, reproduce, grow, adapt, maintain homeostasis
how are differences expressed in eumetazoans (9)
habit (free-living/symbiotic, sedentary/motile, predators/prey)
habitat (aquatic/terrestrial)
symmetry (bilateral/radial)
segementation of body parts
tissue organization
coelom
embryonic development
organs (gut is either a cavity or tube)
organ systems (open/closed circulatory system, nervous system, reproductive system (external/internal, direct/indirect)
sponge phylum
phylum porifera
how is a sponge’s body organized
around a series of holes and channels to accomodate water flow
how does a sponge’s body organization help it survive
allows sponge to use water as a mechanism for nutrients by increasing surface area
water flow in a sponge
enters through ostia - flows through many small passageways - exists through osculum
how is water current maintained in sponges
choanocytes (flagellated cells) that line the passageways and trap food particles
what is the advantage of having a complex system of water channels
gather food, respiratory exchange, removal of waste
other cells in sponges (3)
porocytes, amoebocytes, epidermal cells
how do sponges protect themselves if they are sessile
colour, produce toxins, regeneration
how do sponges reproduce
asexual - budding/fragmentation
sexual - spawning
what phylum are cnidarians
phylum cnidaria
examples of cnidarians
jellyfish, sea anemones, corals
are cnidarians herbivores or canivores
marine carnivores
cnidarians symmetry
radial
2 body forms in cnidarian life cycle
medusa and polyp
how many germ layers do cnidarians have
diploblastic (ecto and endoderm) - epidermis and gastrodermis
what are cnidocytes and what are they used for
stinging cells - aid in capturing prey, detecting predators
do all colonial cnidarians have the same type of organism in one colony
no! different individuals have different functions
how is genetic variation perpetuated in life forms without medusa
gametes are produced by polyp and released into water for external fertilization
what are the two subdividions of phylum cnidaria
medusozoans and anthozoans