Bio 124 Fall 2015 Study Questions for Midterm #1
Midterm #1 is Tues 9/22/15 in lecture EBS 309: bring a 100 question scantron & a #2 pencil
This exam covers material from lectures #1 (8/25/15) through #8 (9/17/15)
Use these questions as a guide to key concepts - be sure to review your notes from class and the book.
Help yourself study by meeting with a study group – test each other and try to answer and explain the
questions to each other. Re-read and re-write your lecture and text notes. Ask questions of me and
your peers in study groups about anything you do not understand.
Lecture 1 (8/25/15): Introduction; Ocean basin topography
1. List 5 different reasons that the ocean is important.
2. What is the main cause of variation in water temperature around the California Channel
Islands?
3. List the 5 oceans. Where do all but 1 directly connect?
4. Define: pelagic zone, neritic zone, oceanic zone, benthic, photic zone, aphotic zone.
5. Briefly define each of the following aspects of ocean topography, describe the general
characteristics, and note the % of the seafloor each covers: continental shelf, shelf break,
continental slope, continental rise, abyssal plain, seamounts & guyots, mid-ocean ridges,
trenches.
6. For next class, define: salinity, heat capacity, atom.
Lecture 2 (8/27/15): Challenges of ocean life; Water Properties; Salinity
1. List 6 natural aspects of the marine environment that create unique challenges to marine
organisms. Briefly explain how/why each is a challenge.
2. List 2 unique properties of water.
3. Describe the basic structure of an atom, listing each of the 3 subatomic particles, noting the
electrical charge for each.
4. What is an electron (aka valence) shell?
5. Define element. What determines whether an element is stable or unstable?
6. Why are oxygen and hydrogen atoms so attracted to each other?
7. Define covalent bond & hydrogen bond.
8. Define polarity and explain why water has this property.
9. For virtually all substances, density is higher in the solid form compared to the liquid form.
Explain why water does not have this property.
10. Define: heat capacity, salt, ionic bond.
11. What causes water to have high heat capacity?
12. What does the fact that water has high heat capacity mean for the oceans and the planet?
13. Why is water so good at dissolving salts?
14. List 3 sources of salt into the sea.
15. What is the average salinity of the ocean? (be sure to write out the units fully)
16. What is a pycnocline? What tool is used to survey this?
Lecture 3 (9/1/15): Osmotic Regulation; Temperature; Ocean Layering
1. Define the Rule of Constant Proportions and explain why it is so important to marine life.
1. Define: diffusion, osmosis, cell/plasma membrane, semi-permeable membrane.
2. Why can water pass thru cells via the process of diffusion but solutes cannot?
3. What is the difference between an osmoconformer and an osmoregulator? Provide examples of
each type of organism.
4. List the 3 different main methods of osmoregulation and provide an example of each one, noting
the type of organism that does that.
5. What will happen to an osmoconformer if placed water that is more salty and if placed in water
that is less salty?
6. Define: thermocline, ectotherm, endotherm.
7. Are most marine organisms ecothermic or endothermic? Why?
Lecture 4 (9/3/15): Thermohaline Circulation; Pressure; Dissolved Gases; Light
1. What 2 factors influence the density of water?
2. Define: Pycnocline; water mass fingerprint; haline.
3. What are the 3 layers of the ocean? Note the general depth range and basic temperature
properties of each.
4. What is thermohaline circulation? What factors drive it?
5. What conditions create a stable water column and which create instability? (ie., why
downwelling occurs and how/why it creates overturn)
6. What is the Great Ocean Conveyor (GOC)? List the 2 places it begins, explain why that
happens, and describe its path.
7. List 2 key roles of the GOC play for Earth & ocean ecosystems.
8. Describe how pressure changes with depth. Define an ‘atmosphere’ (atm) (when referring to
pressure in the ocean) and state how much seawater equals 1 atm.
9. Why do many deep dwelling fish die when brought to the surface quickly?
10. Are gases more soluble in cold or warm water?
11. Define conservative and non-conservative gas.
12. State why each of the following gases are important for life, whether they are conservative or
non-conservative, and what their sources and sinks (things that add and remove them) are in
the ocean: nitrogen, oxygen, carbon dioxide.
13. Draw a depth profile of O2. Note which biological factors increase and decrease its levels in
each section of the graph.
14. What is the oxygen minimum zone (OMZ)? Explain why the oxygen levels are high or low in
each of the 3 layers of the ocean.
15. What depth range is the photic zone?
16. Why is the photic zone shallower in some areas (e.g., the neritic zone)?
17. Which wavelengths (ie., colors) of light get filtered out most quickly with depth? Which
penetrate the deepest?
Lecture 5 (9/8/15): Light; Basic Biology
1. Define: homeostasis, metabolism, organic compound
2. Which property of water allows it to be the basis of life?
3. Briefly describe each of the following 4 types of organic compounds: carbohydrates, lipids,
proteins, nucleic acids. Note their main ingredients & what roles they play for biological
organisms.
4. Write the basic ‘equations’ for photosynthesis & respiration.
5. Define primary production. Why is it important?
6. Define: autotroph, heterotroph, chlorophyll, organelle, carbon fixation, glucose, nutrient,
micronutrient, macronutrient, limiting nutrient.
Lecture 6 (9/10/15): Nutrients; Atmospheric Circulation
1. Create a simple diagram or description of the carbon cycle in the ocean. Be sure to list sources,
sinks, and the processes that drive the cycle. Note what carbon is needed for in biological
organisms.
2. What are the 2 sources of nitrate in the ocean? What is it needed for?
3. List 8 critical nutrients & a state a source of them and what they are needed for.
4. How are nutrients recycled?
5. What causes nutrients to be depleted in surface waters?
6. What limits nutrients from being replenished in surface waters?
Lecture 7 (9/15/15): Surface Circulation ;Gyres
1. What causes high pressure zones? What causes low pressure zones?
2. High and low pressure zones are set up on the Earth at the equator, 30N & S, 60 N & S, and 90
N & S latitude. Draw a globe and note which latitudes are high and which are low pressure
3. Do winds blow toward or away from a high pressure zone?
4. Which direction do winds flow in area between the equator and N or S 30° latitude, of the planet
(trade winds)? Why?
5. Describe what causes the Coriolis Effect.
6. Which direction does the Coriolis Effect cause air & water to turn in the northern vs. southern
hemispheres?
7. Define current. What is the major force driving surface ocean currents?
8. Which current flows unimpeded around the globe?
9. What is an oceanic front? Why are oceanic fronts ecologically important?
10. Describe an ocean gyre and state what factors cause it to flow the way that it does.
11. List where each of the 5 major gyres occur, noting which direction each rotates.
12. State where Eastern & Western Boundary Currents occur and how they differ in terms of
temperature, current speed, & volume.
13. What 3 physical conditions can be found in gyre centers?
14. Gyre centers tend to be low in nutrients in the surface waters. Explain why.
Lecture 8 (9/17/15):Ocean Circulation; Epipelagic ; Productivity
1. Describe the Ekman Spiral, noting the forces that drive it.
2. Define upwelling. List the 2 different processes that can cause it & briefly explain how each
leads to upwelling.
3. Vertical circulation in the oceans can be caused by 2 different factors. List them.
4. Describe the situations in which wind can drive a) coastal upwelling and b) coastal downwelling
(be sure to take into account the direction of the wind relative to land and the hemisphere)
5. Describe why upwelling occurs along the equator.
6. What benefit does upwelling provide for surface organisms?
7. List the depth range and key property of the epipelagic zone.
8. Define neritic & oceanic zones in terms of location and general properties.
9. Define: epipelagic. Photic zone. plankton, nekton, neuston, phytoplankton, zooplankton.
10. Define primary productivity.
11. What 2 key factors allow primary production to occur?
12. List the processes that can limit each of those 2 key factors.
13. State when blooms of phytoplankton occur in each of the 3 Earth zones: the poles, temperate
areas, and tropics. How does the physical environment of the ocean limit or allow blooms to
occur when they do?