Zoology Lab ?s

How must Trypanosoma organism obtain their nutritional requirements?

Absorbs nutrients from surrounding body fluid.

A doctor suspects that you might be infected with Trypanosoma. Name 2 places that you might recently have visited that would help decide what species of Trypanosoma you are carrying.

Africa & South America would be places where they may be formed. (Especially in tropical areas)

What key characteristics is possessed by all species of the genus of Trypanosoma?

All live in the blood or other tissues of their host.

What's the functions of choanocytes?

Are flagellated collar cells that create a water current through the sponge and remove food particles form the water.

Describe the pathway of water through Sycon, naming all canals & opening through which water passes from entrance to exist.

Dermal Ostium, Incurrent Canal, Porsopyle, Radial Canal, Apopyle, Spongocoel, Osculum

What is the single anatomical feature whose presence or absence will distinguish hydromedusae from scyphomedusae?

Hydromedusae have a velum.

Were the colonies you examined reproducing asexually or sexually? (Volvox)

I believe most of them were reproducing asexually, & didn't see a lot of them with little black specks.

On what does Aurelia feed? Describe how food is captured conveyed to the mouth.

It feeds mostly on zooplankton. Food organisms are caught in mucus secreted on the subumbrella and moved by cilia to the bell margin. Food is collected from the margin by the oral arms and is transferred by cilia to the stomach.

What is the main function of the contractile vacuole? (Ameba)

It gets rid of excess water.

How does hydra respire? How does hydra excrete nitrogenous wastes?

It respires through its the endoderm and ectoderm, it removes nitrogenous wastes also through the endoderm and ectoderm.

Describe the different forms of movement & locomotion in Euglena.

It uses its flagellum to swim around like a whip. It also uses Euglenoid movement to change into a "worm-like" movement. It also changes shape.

How does Euglena satisfy its nutritional requirements?

It uses photosynthesis like a plant.

Does Aurelia have special organs for respiration and excretion? How does gas exchange occur in Aurelia?

No they don't, just for eating and digesting, gases just move from its skin.

Would you expect Trypanosoma to have a system for digesting food like amoeba? Why or why not?

No, it gets all its food from the surroundings.

What is the advantage to a sessile animal of producing free-swimming larvae? What would be the disadvantage to sexual budding being sole means of production?

So the larvae can go away from each other so they aren't all competing for resources. It would also be an advantage because it would mix up the gene pool to create more variation.

What is the sexual stage in the life cycle of Aurelia, the asexual stage? Which stage is dominant in the Aurelia life cycle?

The Scyphistoma-Strobila is the asexual stage of reproduction, while the zygote on the Medusa that develops into a ciliated planula larva is the the sexual stage of reproduction.

Do amebas react to stimuli & what have you observed?

The alive ones do, and they don't like light.

To what class of sponges do most marine sponges belong?

The class Demospongiae is what most belong to.

How does the ameba respire?

The ectoplasm absorbs oxygen & gets rid of carbon dioxide.

What is meant by the term "dimorphism"

The presence in a species of more than one morphological kind of individual.

Using the average diameter of the mammalian red blood cell (7.5 μm) as a guide, what do you estimate the length of Trypanosoma to be?

They are about 20-30 μm (all straightened out) in length.

In what ways does a sponge show evolutionary advancement, as compared with a colonial protozoan, such as Volvox?

They are bigger with different jobs of parts for different cells.

To what level of organization do sponges belong?

They are multicellular, or metazoan.

In what ways is Volvox similar/different to Euglena

They both undergo photosynthesis & are both "kinda plant, kinda animal." Volvox are bigger & more round. Euglena are more pill shaped & have a flagellum & more organelles.

What characteristics possessed by Trypanosoma organisms would tell you that they belong to the phylum Euglenozoa?

They have a flagellum.

Describe the process by which young medusae are produced.

They produced when a ciliated planula larva settles on a rock and develops into a Strobila and then falls off one by one on the 'stack' that is the Strobila

How does the ameba reproduce?

They reproduce asexually using binary fission.

What is the average size of specimens on your slide? (Ameba)

They were about .05mm across.

What is the average length of of Euglena in your culture?

They were about .1-.2 mm in size.

What type of tissue would a doctor collect to test to see if you have Trypanosoma?

They would take a blood sample.

What function might the stigma Euglena serve?

To know where light is so it can undergo photosynthesis with its chloroplasts.

What drives the flow of water through a sponge?

Using small cilia to help push it through.

Cnidarians are "diploblastic." What does this term mean?

When the epidermis and gastrodermis develop from the two embryonic germ layers, ectoderm and endoderm, respectively.

Explain how the 2 forms of reproduction in sponges, sexual & asexual, deffer from each other.

With asexual reproduction, a new one simply buds off & creates a new offspring, while sexual takes 2 to tango & creates a large bulge in a female similar to humans.