BIO 20: Exam 2 Essay Questions
Four of these questions will be on the exam and you will choose to write on three out of the four. Each of the
three questions will be worth 8 points on the exam.
1. A) Describe the main difference between autotrophic bacteria and heterotrophic bacteria.
B) Give one example of a marine autotrophic bacteria that we discussed in class.
C) State why scientists believe this marine autotrophic bacteria is especially important in terms of our
planet’s atmosphere.
2. A) State the common names of the two types of unicellular algae that we discussed.
B) State two characteristics that describe each type of alga.
C) State two reasons why unicellular algae are important to have on our planet.
3. Read the online article “The Ocean’s Invisible Forest” and answer the following:
A) How much carbon dioxide does phytoplankton draw out of the atmosphere and oceans compared
to land plants?
B) Briefly describe how the global carbon cycle has fallen out of balance.
C) State one advantage and one disadvantage of fertilizing the ocean.
4. State the name of these basic structures of this alga in the diagram and state the function of each
structure.
5. A) In terms of evolution, state why green algae are important and list two characteristics that green
algae share with land plants. Hint: look at Table 6.1.
B) List the three types of flowering plants that inhabit marine environments.
C) List three important services (or functions) that these flowering plants provide to ecosystems.
6. A) List the three seaweed phyla
B) State the dominant pigment that is found in seaweeds from each phylum.
C) State where seaweeds from each phylum are generally found.
7. A) State the scientific name of the invasive green alga that we discussed in class (remember: underline
or italicize scientific names, upper case genus name, and lower case species name
ex. Homo sapiens or Homo sapiens).
B) Give two specific examples of how this alga is a threat to invaded ecosystems.
C) Briefly describe how Southern California dealt with their invasive alga outbreak and whether it is
now under control (read online article “Biologists Score Rare Victory Under the Sea”).
8. A) State the names of the three phycocolloids.
B) State the type of algae (i.e. green, red, brown) that is the source for each phycocolloid.
C) State two general uses of phycocolloids.
9. According to the video “Algae Fuel”:
A) Photosynthesizing algae produce oxygen, sugar, and what other product which can be converted
into biodiesel (biofuel)?
B) What are the two major disadvantages of producing corn based ethanol as biofuel?
C) What is the advantage of producing algae for biofuel?
D) What is the disadvantage of producing algae for biofuel?
10. State the 3 classes of molluscs that we discussed and give two animal examples for each class.
11. A) State the largest phylum of animals.
B) List two unique characteristics that distinguish this phylum from other phyla.
C) State the subphylum within this phylum that includes those that are adapted to live in water.
D) Lastly, list two animals that fall within this subphylum.
12. State the 4 classes of echinoderms that we discussed and give one animal example for each class.
13. A) State the subphylum that falls under the Phylum Chordata and includes tunicates (sea squirts).
B) Explain why animals in this specific subphylum fall under Phylum Chordata.