Biology 121: First Mid-term Study Guide

The topics listed below have been discussed during lectures and are subject to multiple choice questions. In addition the topics for short essay questions are listed. Your notes should have all, and your textbook most, of the information pertinent to the examination. The exam is on material up to and including the phylum cnidaria, unless changed in class this week..

Potential Essay Questions (Number 4 below will be required)

1. Porifera (Sponges).  Describe the structure of the porifera (sponges) and how they feed. First describe the structurre, including the three tissue-like layers, and then how they feed, including how the feeding current is produced and how food is captured.

2. Nutrient Cycles.  Be able to describe nutrient cycles (either phosphorous or nitrogen) and the role of bacteria/microbes in these nutrient cycles. Explain using both a figure (drawing) and verbal explanation.

3. Thermocline.  Be able to: (1) define the thermocline, (2) explain differences in the occurrence of the thermocline in different latitudes (tropics, polar and temperate), and in seasonal variation in the temperate zone, and (3) the effect on nutrient availability and biological productivity.

4. Upwelling.  Be able to define upwelling. Describe the general location and the mechanisms of upwelling due to (1) the Equatorial Counter-current; (2) prevailing offshore wind transport; (3) headlands; and (4) converging surface currents. Include a discussion of the effect of upwelling on nutrients and the biological effects (productivity).

The following review questions may assist you in your exam preparation.

* What is the percentage of the earth's surface covered by water?
* In what region of the ocean are most of the fisheries are located?
* What is the average depth of oceans and what is the deepest depth of oceans?
* What is the proportion of the different salts in the world's oceans?
* How does the amount of gas change in water as the temperature and salinity change?
* What gas is produced by the respiration of decomposers and animals?
* How does salinity vary in different bodies of water?
* How does the amount of heat required to change water compare to air and land?
* How do sessile benthic organisms disperse their propagules (larvae, spores,etc.)?
* Radial symmetry is common among organisms with what type of habits and feeding mode?
* What is the underlying theory for the modern scheme for the classification of life?
* What is a species name and how many words is it?
* What is a raptorial predator?
* What is deposit feeding?
* Marine phytoplantkon is composed primarily of which single-celled plants?
* What are the potential effects of a "bloom" of certain species of dinoflagellates?
* How do the very large kelps off our coast hold themselves up in the water column?
* Which algae off our coast exists as a microscopic gametophyte and very large sporophyte form?
* What material makes the cells of the coralline algae hard and resistant to physical damage and grazers?
* What are the chemical compounds the produce bioluminescence in the dinoflagellates?
* What are the two different means by which members of the red algae division may discourage grazers?
* What are the overall life history characteristics of the green algae and what do we call this strategy?
* Members of which division of algae would you expect to find growing beneath the shade of a very heavy kelp canopY
* What is the nutrition mode of the foraminifera and radiolaria?
* What is the cause of hydrogen sulfate gas (rotten egg odor) that may be smelled in some marine sediments?
* What types of organisms form the bottom of the food chain in the deep sea hydrothermal vent communities?
* In what part of the oceans are radiolarians found exclusively?
* On what do the foraminifera and radiolaria feed?
* A shell-like test or frustule of silicate is found in which group of planktonic organisms?
* What is the most nutrient for the growth of plants in the oceans?
* Bacteria and cyanobacteria must "fix" which nutrient from the atmosphere?
* The cycling of nutrients released from tissues is due to the action of which group of organisms?
* How do you define the thermocline?
* How does the thermocline vary in the world's oceans over the different latitudes?
* How do ocean currents influence the distribution of organisms?
* How do counter currents affect the distribution of some midwater (deep sea) fishes?
* Where are nutrients found when the water current is strongly temperature stratified?
* When are nutrient conditions the best for growth of phytoplankton in the oceans of the temperate zone?
* What are the three causes of upwelling?
* What is the term that is applied to the environmental zone on the bottom of the ocean?
* Where is the nearshore of neritic zone of the oceans?
* What is the mesopelagic environmental region of the water column?
* How do you define the planktonic habit of marine organisms?
* Shrimps, rays and skates can swim up off the bottom and are said to have what type of habit?
* Which two classes or types of cnidarian may have a theca or hard skeleton?
* What cell in the sponges both captures and engulfs food particles?
* What algae "cements" coral reefs together?
* In the temperate zone, under what types of light and substrate (attachment surface) conditions are you likely to find sponges?
* What plant and animals that you have studied have two distinct life forms to their life cycle?
* Nematocysts are used by what types of animals ?
* What organisms commonly eat sponges?
* The siphonophores, such as the Portuguese Man-of War are made up of what two forms of cnidarian?
* What are the two stages of the complete potential life cycle of cnidarians (jelly fish/hydroids)?
* How do soft gorgonian corals feed?