lab exam 1

dinoflagellates

Group of protists that form "blooms", can be toxic. make up phytoplankton and can be bioluminescent. They generally have two flagella, half are heterotrophic and the other half are photosynthetic, many species are luminescent

what is coccidiosis

a disease of the intestines caused by coccidia parasites

where is the pharynx located?

abdomen area

why does taenia lack a thickened muscle layer in the body wall?

absorb food through their bodies

what is the function of the medusa bud? how does it escape the gonangium?

allows the species to disperse to different locations; released through gonopore

what cells are the most important in forming a new sponge? why?

archeocytes because they deal with reproduction

what is the purpose of the micropyle?

area in surface of egg where sperm enters

how do cercaria get into the definitive (final) host?

burst from snail and swim freely in water then penetrate humans

what is a miracidium and how does it swim?

ciliated larval stage; swims using cilia

is physalia physalis a colony or an individual? explain why this is true

colony because many different animals

what is a pinacocyte and where is it found?

contractile flat cells that regulate flow into sponge; phagocytize some food on sponge surface

what is the purpose of the siphonoglyph in anemones?

create currents of water into the pharynx

how do planarians feed? are they parasitic?

digestive enzymes released and suck up remnants. not parasitic because doesn't live in host

difference between diploblastic and triploblastic; which describes sea stars and frogs?

diploblastic only has two germ layers; triploblastic has three; sea stars and frogs = triploblastic

how do physicians test for the presence of a tapeworm parasitic?

examine stool samples

leucosolenia has choanocytes inside its body. define choanocyte and describe its function

flagellated cells that line internal chambers of sponges; flagellum beats and water current brings food in

what happens in the gastrovascular cavity? where do indigestible wastes go?

food distributed to colony through cilia; excreted through the mouth

how does the planula stage swim? what is its function?

free-swimming; drifts; some crawl; develop into a polyp

how do the gonangia and developing polyps get food without possessing nematocysts?

from gastrovascular cavity distributing the food with cilia

what structure on the hydroid colony produces the medusa stage?

gonangium

briefly explain how hydranth and gonangium polyps (structure and function) are different

hydranth is for feeding, gonangium is for reproduction

how are radial canals different from the incurrent canals? why is this important?

incurrent are lined by flat squamous cells and only form water conduits and a smooth, firm surface radial canals are lined by collar cells opening at the surface and are provided with flagella or whips controls fluid in sponge

what is the purpose of a gemmule? where are they commonly formed?

internal buds involved in asexual reproduction; produced in internal buds or archeocytes

how is the animal pole different?

it splits faster than the vegetal pole and has 4 small blastomeres. it contains very little yolk and is mostly cytoplasm

define mesohyl. what types of cells/structures would you expect to find there?

jelly-like layer that contains archeocytes

which of the three body forms do you see in these large, dried sponges?

leucon body plan

where does the adult clonorchis live (in the human body)?

liver

list and describe two characteristics of scyphozoans. how are they different from hydrozoans?

medusa lacks velum, nematocysts in epidermis and gastrodermis

what jellyfish stage comes after the ephyra stage?

medusae

how are the macronuclei and micronuclei different? general functions?

micronucleus is for reproduction; macronucleus is for other functions

what is the purpose of the apical complex?

motility, host cell invasion, intracellular survival

list and describe two characteristics of anthozoans. how are they different from hydrozoans and scyphozoans?

nematocysts i'm gastrodermis and epidermis, venom is neurotoxic, no medusa only polyps

what are the two main characteristics of Hydrozoans?

nematocysts only in epidermis, medusa has a velum

what happens to ectoderm during development

neural folds are ridges of ectoderm that rise upward, fuse and create a neural groove neural tube forms when the folds above the groove close at the top neural tube forms the brain, nerves, eyes, and spinal cord neural crest cells pinch off from the neural folds & form sensory nerves of the autonomic nervous system and also the skull & jaw bones

can gonionemus sting prey held in its gastrovascular cavity? why or why not?

no because nematocysts are only in tentacles

what do we mean when we state that cnidarians are diploblastic?

no mesoderm; only two germ layers (but have mesoglea)

does the portuguese man of war steer toward food? why or why not?

no. catches prey along its path

do comb jellies have nematocysts? if not, how do they get food?

no. colloblasts stick ti prey and into mouth

frog early cleavage

often has an outer protective jelly layer, small and large blastomeres, animal pole, vegetal pole; smaller blastomeres are at animal pole, vegetal pole that is rich in yolk divides slower

where are the cilia on vorticella?

on the oral end

what is the name of the openings where old/used water exits?

oscula

frog late cleavage

outer protective jelly layer, small blastomere, large blastomere, animal pole, vegetal pole; smaller blastomeres at animal pole

ceratium

part of dinoflagellate; mixotrophs; has distinct shape "arms" and "horn"; relatively harmless

what is the only polymorphic form seen in anthozoans?

polyp form

list and describe the five main characteristics of cnidarians

radial symmetry- sensory structures distributed around body diploblastic organization- ectoderm, mesoglea, endoderm nematocysts- coiled, hollow tube, usu. neurotoxin polymorphism-polyp and medusa form nerve net- 2D under epidermis, touch, balance, photoreception

how do humans contract clonorchis? is this a different method from schistosoma?

raw or undercooked fish. human has to swim in infected water for schistosoma

what are the purposes of the scolex and strobila?

scolex-anchors into intestine strobila-segments of body

what life stage immediately follows the planula stage? what process (mitosis or meiosis) permits the formation of this next stage? explain

scyphistoma; mitosis

find the rhopalium; what is its function?

sense light and movement or direction with respect to gravity

is the planula the result of sexual or asexual reproduction? who were the parents?

sexual; male and female releasing egg and sperm

what two animal species serve as intermediate hosts? what animal is often the final host?

snails and fish are intermediate. human is final

what two types of cells are important (male/female) in sponge reproduction? which one resembles animal sperm and which functions like an egg cell?

sperm and egg gametocytes

examine the natural bath sponge. what structures must be removed before this sponge is used for bathing? how is this accomplished?

spicules; scraping the sponge

what is the purpose of spicules found in the body wall?

support sponge, enhance reproduction success, catch prey, help larvae stay buoyant

what is meant by a gravid proglottid?

takes up much of the space and very visible

what happens to a portuguese man of war if it is stranded on the shore?

the cells can still fire

planaria

the class of free-living flatworms

what is a spongocoel?

the large central cavity of sponges

what is a test?

the skeleton made cellulose in a dinoflagellate; protective shell

why is it possible to be stung by physalia when one cannot see the float animal?

the tentacles can reach 75 ft

why are true jellyfish considered plankton? what does this mean?

they are drifters; living things in water that can't fight a current

why are radiolarians more restricted in their movements than a typical freshwater amoeba?

they are non-motile and drift through water currents

do anthozoans have nematocysts? how do corals get food (other than killing it)?

they do have nematocysts, but get food from algae (zooxanthellae)

why are their tests easy to distinguish from other protists?

they have holes in them

how are their nuclei different from other protists?

they have two nuclei

how does hydra know to fire its nematocysts if it lacks a central nervous system?

they sit right under the ectodermis, being the outer body wall and nervous system

what is the purpose of the float animal?

to keep the animal buoyant

how do living ceratium move?

two flagellum; one pulses, one beats in a spiral motion

why are ascon sponges smaller than other large sponges?

vase-like; small surface area of choanocytes; no folds

what do solitary radiolarians eat?

zooplankton, phytoplankton, detritus