Cnidaria
How do Cnidarians swim?
By contracting myoepithelial cells against the mesoglea. The contraction pushes the water in the bell out like a jet.
What are the components and the function of a choanocyte?
Cell body with a collar made of microvilli and a flagellum.
Choanocytes generate currents to circulate seawater w/in and through the sponge and to capture food particles.
Ctenophora dosen't have mesoglea but they have something similar. What is it?
Mesenchyme (like mesoglea but its cellular)
What are neoblasts and what is their function?
Undifferentiated cells with versatile development and they are used to regenerate.
What is a coelom and what does it do?
An internal, fluid filled body cavity lined with mesoderm. Functions as a hydrostatic skeleton, can aid in distribution of nutrients and oxygen, oftern contains gonads and excretory system.
The hard statolith will lean on cilia in the statocysts which will send a signal telling the organism it is leaning and to swim the other way.
What is the function of archaeocytes?
They move through the mesohyl and digest food caught by choanocytes, eliminate waste from sponge, can turn into other cells.
Draw and label a ctenophore.
look at notes
How do they move?
1. surface ciliated, ventral cilia and mucus help slither.
2. pedal waves (head to tail)
3. Looping
How is the proboscis released?
It is housed in the rhynchocoel surronded by circular muscles and when they contract it forces the proboscis out then the muscles at the base of the rhynchcoel contract to pull it back in.
Draw the life cycle of a scyphozoan
I can't upload a picture
Describe the movement of water in a leuconoid.
Water is brought in through ostium where it is moved by choanocytes in the choanocyte chamber and is then sent out through the osculum.
What controls the comb rows and how does it work.
The apical sensory organ controls the comb rows. The dome contains a statolith on balancers. When the ctenophore is off center the statolith will put pressure on the balancers which will send a signal to move the combs rows to straighten out.
Descibe the different haptors in the class monogenea
Opisthaptor: specialized posterior attactment organ. Prohaptor: anterior adhesive organ.
Name four characteristics of nemertea
triploblasic
coelomate
bilateral symmetry
unsegmented
complete digestive tract
proboscis
closed circulatory system
Draw the life cycle of a anthozoan
Check notes
Describe the structural support system (including all components and their function) of a demosponge.
Primarily organic matrix like spongin, collogen or mesohyl. Also siliceous spicules for more hard structure. Spongin form most of the skeletan frame and spicules are used for detering predators, maintaining shape and support.
Describe how ctenophores move.
1. via sychronized flapping of comb rows
2 muscle contraction
Muscles in the mesenchyme, circluar and longitudinal muscles just beneath epidermis
Define trophic transmission
definative host must eat the intermediate host containing the parasite.
What is the difference between order monostilifera and order polystilifera
Polystilifera: many stylets
Name and describe two structures that would help you determine if a medusa is a hydromedusa or a scyphomedusa
Hydro had a velum scypho does not. Velum is a shelf of tissue that helps w/ jet propulsion.
Scypho has oral arms and hydro does not. Oral arms are tentacle-like structures around the mouth to bring food to the mouth.
Scypho has 4 gastric pouches that help digest food by using gastiric fillaments which are tenticles w/ neumatocyst that secret digestion enzymes.
Define syncytial.
Lots of nuclei within a single cell membrane.
How do species with tenticles eat?
How do species without tenticles eat?
With tenticles: extends tenticle to grab food using its colloblast cells and brings the food to it's mouth.
Without tenticles: Large oral lobes covered in mucus and colloblast cells and auricles which are ciliated paddle-like structure on either side of the mouth to bring prey in.
Decribe and draw protonephridia
Notes
Draw and label a nemertea
Notes