Title: Assignment: LAB - Animals (pt 2)
Course: BIO-182 RTZ

COCONINO COMMUNITY COLLEGE

Bio182 - ANIMALS - continued

There are two major groups of bilateraly symmetrical triploblastic animals: the protostomes and the deuterostomes.  Protostomes are distinguished from the deuterostomes by two developmental characteristics: 1) during gastrulation, the initial pore that forms (the blastopore) becomes the mouth and 2) if a body cavity (coelom) forms later during development, the cavity arises from a splitting of the mesodermal cells rather than pinching off, as in the deuterostomes.

As with the plant portion, there are two sections to each lab: 1) a few questions to answer online (5 pts) and 2) an in-class portion examining representative organisms of different phyla (10pts). The in-class portion gets incorporated into the portfolio.

QUESTIONS:

1. (1) People who eat raw clams and oysters harvested from sewage-polluted waters often develop mild to severe gastrointestinal infections. These molluscs are suspension feeders. Develop a hypothesis about why people who eat them raw may be at risk.

2. (2) What are the relative advantages and disadvantages of radially symmetrical and bilaterally symmetrical body plans?

3. (2) Use your understanding of protostome evolution to discuss two adaptations for terrestrial living that also occurred in land plants. (what are they and why are they adaptive?)