Exam 3 Lab Stuff

Why is mixotrophy an adaptive trait?

Use light as energy when available and organic compounds otherwise

Define parasitism.

An organism lives on or in another organism and derives nutrients from it

How do trypanosomes obtain energy?

Absorb glucose directly from host's blood

Example of endoparasite.

Tapeworms

Example of ectoparasite.

Lice

What advantage and disadvantage do cellulose plates provide for dinoflagellates?

Protection; synthesizing plates takes a lot of energy

How are flagella different from cilia?

Longer, whip-like motion

Example of diseases in humans spread by mosquitoes.

Malaria, West Nile Virus

How is sexual reproduction different from asexual reproduction?

Offspring genetically different from parents (vs. clones)

How do sponges move into new areas?

Fragmentation: piece breaks off, carried by current, regrows in new place

Based on the appearance of Spongia, what is the primary component of their skeletal network?

Spongin

How is phylum Cnidaria different from phylum Porifera?

Forms tissues and symmetry

How do solitary cnidarians move?

Slowly, typically only their tentacles

How do solitary cnidarians' movement help protect them from predators?

Small, slow movements help them stay undetected/hidden

Are the segments of a clamworm the same size (approximately)?

Yes

What purpose could there be for the knobs, ridges, or spikes on a shell?

Used to fend off predators

How are gastropods structurally different from bivalves?

Bivalves do not have a radula

What features identify a mollusc as a scaphopod?

Tubular shell open at both ends (tusk shells)

How would you describe the test of a sea urchin?

Has lots of little spikes on it

How would you describe the test of a sea dollar?

Smooth, has five "petals" on it