1. Review the Concepts of Ecology, Community, and Population

STUDY GUIDE Chapter 10 Castro & Huber

Recommendations to follow: 1. Answers are thought to be short in most of the cases 2. Try as much as you can to connect the terms and understand the association between some of the concepts, to get the whole picture about the topic. Memorizing alone can give you probably around a 70/100 in the exam, but some questions always require to connect two or more ideas to come up with a short and precise answer. 3. If you know most of these review questions you should do fine in the test, questions in the test will be variations of the same themes covered in these questions.

Chapter 10: Marine Ecology

1. Review the concepts of Ecology, community, and population

2. Differentiate between the two possible modes of reproduction: sexual and asexual. Point the main advantages and disadvantages of each one.

3. a) Explain why populations cannot grow indefinitely.

b) What is the “carrying capacity” of a population?

4. What is a limiting factor?

5. a) The population growth curve shows the theoretical change in population size over time, sketch one and explain what causes the three phases.

b) Mention the factors that can produce an increase or decrease in the population number

c) Relate the carrying capacity with the stable equilibrium phase of a population growth curve

6. Briefly explain all the possible ways species can interact and what is the effect of that interaction on each one of the interacting organisms.

7. Why is “larval ecology” so important when considering marine animals?

8. What type of organisms are autotrophs or producers in the marine ecosystems? What organisms are heterotrophs in the marine ecosystems?

9. What is a food chain?

10. Why is more accurate to refer to a web chain instead of a food chain?

11. Trophic level is the general name for each step of a food chain. What organisms occupy the first trophic level? Which ones occupy the second and third?

Marine Biology Instructor: Jose Bava, Ph.D

STUDY GUIDE Chapter 10 Castro & Huber

12. Decomposers are organisms that break down non-living things into its original components for producers to reuse them. What types of organisms are decomposers?

13. For food chains and food webs…

 Name an organism that would occupy each of the following trophic levels: producer, second trophic level, and third trophic level

 Both second and third trophic levels are generically called ______. What is the difference between them?

 What trophic components of communities cannot be represented in a food web but can appear in a food web_ Explain each one of the two possible ones mentioned in class

 What is a “keystone” species? explain

 Which trophic level contains the largest amount of energy? Why is that?

 What percentage of energy is actually passed from one trophic level to the next? What happens to the “lost” energy?

 Based on the previous, what type of food would feed more people for example? Corn or beef? Explain

14. Briefly, explain why the representation of the energy in a food chain has a pyramidal shape with the producers being the base of the pyramid and the top predators being the top

15. a) What parts of the ocean are the most productive ones?

b) What parts are like desserts in the middle of the ocean?

16. What types of organisms are the only ones able to convert molecular nitrogen to a form that can be used by other living things?

17. Explain the concept of microbial loop and its relevance when considering food webs

18. Explain the different types of marine communities

19. Explain the different types of marine ecosystems

Marine Biology Instructor: Jose Bava, Ph.D