Answers to Critical Thinking Questions Chapter 1: The Science of Marine Biology 1. Nearly all of the major advances in marine biology have come in the last 200 years. What do you think are the reasons for this? Reasons include increased mobility due to advances in the means of transportation (faster ships, planes), methodology (sampling equipment, microscopes, scuba, satellites, etc.), developments and discoveries in biology and other fields of science that have stimulated further research in the marine environment (theories of evolution, plate tectonics, etc.), improved educational opportunities and facilities. 2. In this chapter it was explained that the statement "There are mermaids in the ocean" is not a valid scientific hypothesis. Can the same be said of the statement "There are no mermaids in the ocean"? Why? Yes, it is a valid scientific hypothesis because it can be falsified if a mermaid is found. No scientific hypothesis can be proven so this does not mean it is not a scientific hypothesis. So far all attempts to falsify this hypothesis have failed: no one has found a mermaid. Thus, the hypothesis is accepted as true, though not proven. 3. Imagine that you are a marine biologist and you notice that a certain type of crab tends to be considerably larger in a local bay than the same type of crab that is in the waters outside the bay. What hypotheses might account for this difference? How would you go about testing these hypotheses? Let students' imagination roam free, even if they may not know the limitations and constrains of experimental work! It's a great way to stimulate their imagination and desire to learn. One possible hypothesis: "Crabs outside the bay are smaller because wave action outside the bay is stronger than inside the bay." We can reject it if some of these smaller crabs are moved inside the bay, placed in a cage that allows food to move in (as well as smaller crabs from inside the bay placed in identical cages), and all are checked and their size compared after a reasonable period of time. Remember a control experiment: crabs from outside and inside the bay placed in identical cages outside the bay. This hypothesis is rejected if size difference remains when all experimental populations are compared. Other possible hypotheses: differences due to food, predators, parasites, type of substrate, temperature, depth, etc. Do not despair if you cannot come up with too many possible hypothesis&emdash;these factors will be discussed in successive chapters, particularly 10, 11, and 13. 4. Many species of whale have been hunted to the brink of extinction. Many people think that we do not have the right to kill whales and that all whaling should cease. On the other hand, in many cultures whales have been hunted for centuries and still have great cultural importance. People from such cultures argue that limited whaling should be allowed to continue. What is the role that science can play in deciding who is right? What questions cannot be answered by science?
For this activity, students will form groups of three but no more than five virtually and meeting by way of Blackboard*. The teacher would have uploaded material to an existing Blackboard class on Marine Biology that students have access to. If the Blackboard class exists but students are not yet enrolled, the teacher can easily utilize the administrative access through the "control panel" options on Blackboard in order to create users or enroll students for this specific lesson. If an already created course is not readily available, a teacher may research free non-for-credit virtual classrooms offered by nonprofit organizations (Free-Ed.Net) or universities (Open Learning Initiative by Carnegie Mellon University) for something to match their lesson plan.
Once the groups have been formed through a random selection or teacher choice, students will be asked to meet together on a separate occasion to read over the appropriate textbook chapter, discuss the material, and take notes in order to derive factual information on their lesson. Though only the textbook and some external links provided by the teacher on Blackboard will be used for learning, students are expected to still retain the material due to the fact that they will answer a series of teacher created open-ended questions. To help students on their 'learning adventure' they will be looking over a blackboard "learning unit" created by the teacher which provides a series of hints of what to think of or discuss during the process, questions, and diagrams following the Paivio's dual coding theory. Basically, topics for the groups to think over and discuss as they read the textbook material.
So, using hints, the textbook, optional external links provided by the teacher on blackboard, their discussion notes, students will discuss the topic learned, then answer questions and a possible time chapter quiz on blackboard.
- ASIDE: students have the option to meet through asynchronous conferencing tools such as the "Discussion Board" on Blackboard or Blogger for those that possess a gmail account, and/or synchronous conferencing using either a Blackboard Chatroom option or Skype. Note that this option is only possible if all students within the group possess a Skype account and have each others' email information. According to Lapadat's 2002 article "Written Interaction: A Key Component in Online Learning", both types of conferencing are interactive and advantageous to online learning, but the pro of synchronous is that it feels like a conversation but the con is that due to its timed nature, the communication tends to be superficial. In regards to asynchronous conferencing, though it is limited by language, it is not limited by time and therefore student replies will be more in-depth. For the purposes of this activity, the conversation-like communication may offer more advantages, a least for the meeting using our Blackboard "learning unit."
- Example of the Learning Unit: 'Hints, Questions, and Guidance' Once students have studied and discussed the material, they will then be directed to essay questions posted in test-format on Blackboard. The teacher will be expected to publish then remove the questions after a 24 or 48-hour period. Though students worked together in the "study phase" of the lesson, they will be completing the questions individually using their personal Blackboard account setup for the course. Finally, a quiz imported into Blackboard that is timed and randomized may be used as an alternative assessment or a reflective essay.
2. What adaptations do deep sea organisms require that other marine organisms don’t (those living above ?
3. What would be advantages to having whale carcasses on the sea floor? What evidence is there that there are
4. How is it that with a lack of oxygen, deep sea organisms are surrounding by a nutrient-rich atmosphere? In
essence, what nutrients are found in the deeper parts of the ocean? How or why is it that they are found in those
depths. Figure 15.28 may help you with this question.
5. How do the organisms of the deep sea cope with the intense pressure of deep underwater living?
6. What are the general characteristics of a deep-ocean dweller?
7. What are the effects to a volcanic eruption on creatures living in communities around hydrothermal vents? If
it’s even possible, how is it that they can recover from such an event?
8. List the different ocean layers/zones from figure 16.1 that can support primary production.
9. What are the average ocean temperatures for the different ocean zones according to chapter 16?
10. What are nautiloids and what “new trick” did they adapt in order to float up off the bottom of the ocean and
away from predators?
11. Why is it that most deeper ocean dwellers are so small?
12. List and describe the different mollusks (if any) that live in the abyssopelagic layer of the ocean.
13. Pick 3 Abyssinian organisms to describe. Include a description of their anatomy and feeding habits.
14. Why was it so unusual and surprising to scientists that the ocean floor and places such as the abyssal region
can have species-rich communities?
15. “Midwater fishes characteristically have eyes that are large.” Why do you suppose that is the case? What other
‘sensory’ adaptations do these organisms have?
16. Define and describe hypoxia
17. Are deep-sea fishes fast and mobile? Why or why not?
18. Can a person dive using a scuba tank beyond 4000m? Why or why not?
19. What elements do scientists have to face when exploring the deep sea? Also, why is it so important for them to
have such large and heavy suits and/or tanks?
- Test-format essay questions on Blackboard... The questions should be something like the five typed below so that students can work in teams as a study group in order to learn the material, then in order to respond to questions. No two answers should be the same; students may be working in teams, but they are still required to answer each question according to their understanding an personal analysis. Basically they should use their own words!
[The Blackboard Discussion Board (DB) will be used to answer the six following questions]:
(1) What zone(s) was discussed or viewed today? List the organisms viewed and place them in separate ocean zones.
(2) What elements do scientists have to face when exploring the deep sea?
(3) What are the average ocean temperatures for the different ocean zones? How does temperature affect reaction rates (hint: think of the rate at which sugar dissolves in cold versus warm coffee).
(4)Knowing the temperature within the abyssopelagic zone, how is an organism's metabolic rate affected? What does this mean in terms of their eating patterns/habits, in terms of of an organism's movement, and in terms of its size (hint: refer back to ideas put together regarding pressure on the body)?
(5) What are the effects of pressure (large amounts) on the human body? Think of why deep sea divers wear specialized suites before exploring the depths of the ocean...In correspondance to the earlier question, answer, how do the organisms of the deep sea cope with the intense pressure of deep underwater living?
(6) In what way does the average size of organisms change the deeper into the ocean they live? How can you explain this change?
Each student is required to post an answer to each of the questions and to reply a minimum of three times to different students' postings. The DB will be made available for commentaries to be posted throughout the week.
Students will then be asked to move to their final step in this lesson, the reflection...
* this meeting process may be initiated through the classroom if necessary.