BIOS 101
Section: Thursday 1pm
February 2, 2015
1.
a. A chiton is a marine mollusk in the class Polyplacophora. It has a flattened, oval shaped body with a shell of eight overlapping plates. They are usually found clinging onto rocks near water, this way they can obtain their food. Chitons eat algae, diatoms, and sometimes they will also eat bacteria. Chitons have separate sexes. The male chiton releases his sperm cells into the water, and the female chiton releases her cells individually. As a result, fertilization is external.
b. Not much changes between the two places because the chitons are still able to get nutrients; therefore they are able to survive. This result is expected because there are no other species in the cages to compete with the chitons for their resources. The researcher used a statistical test to measure how much longer the chitons near the low-tide mark took to forge compared to the chitons in the normal distribution. A Mantel-Haenzel test is a statistical test in which you are able to compare two variables in a two-by-two table, where each variable has two possible outcomes.
c. One ecological factor that we can take into consideration is the species habitats. Chitons are more likely to live on rocks near or in the water, which is why they have a higher survival in the high tide area. Snails usually live near soil and not in the water, which is why they were all dead at the high tide area after three weeks. Another ecological factor can include nutrients. The chiton has a higher survival rate in the upper intertidal area because they can find their main nutrient, algae, there. On the other hand, a snail will prefer the lower intertidal zone because it is richer in organisms which they can feed on. We can verify this by designing our own experiment, or doing some more in-depth research on the two species and the two locations.
2. The estimated number of soldier flies in this local population is 11,000. A solider fly,