Biology 121: Second Mid-term Study Guide 

The material for this examination starts with the phylum Mollusca and ends with the fishes. You should be familiar with the major features discussed for each taxon, or group, of organisms. You should be able to recognize the scientific names for the phyla, however, the common names of the other groups will be given. The information listed below was discussed in lectures.
 

The following topics may appear as subjects of short essays:
  1. Molluscan body plans: be able to describe the hypothetical ancestral form (major body features and their functions e.g. mantle, shell, visceral mass and foot) and derive the extant (living) classes from it (i.e. describe how each of these features is modified in different classes).
  2. Fish morphology (body forms) and adaptations: be able to draw and describe the general features of fishes - body shape, body regions, fin size and placement, lateral line and be able to design a fishes adapted for a (1) pelagic (oceanic) and (2) nearshore (reef) existence.
  3. Osmoregulation (water balance) in both elasmobranchs and bony fishes: be able to explain the structures and physiology involved in water balance and excretion (nitrogen waste elimination).
  4. Echinoderm body plan, water vascular system, and the structure of the different classes - be able to describe the structure and function of the water-vascular system and the morphology (form) of the different classes of echinoderms we discussed in class.
The following review questions may assist you in your exam preparation.

* What is the general structure of a chiton?
* How do octopuses manage to open up the shells of their prey?
* What muscle is used by bivalves to hold their shells closed?
* What structure forms the siphons of clams?
* How do bivalves such as scallops sense light?
* What class of molluscs possesses a beak?
* How is homing behavior advantageous to limpets?
* What are the adaptations of surface dwelling bivalves?
* What phyla are radially symmetrical?
* What nutrients are limiting to the growth of plants?
* How should an increase in carbon dioxide affect the pH of the oceans?
* How does the type of burrow occupied by a worm affect its feeding mode?
* Fan-like parapodia of worms are used for what function?
* What benthic region would you expect to be dominated by infaunal worms?
* Are echinoderms found in any aquatic system other than the oceans?
* What are the characteristics common to all echinoderms?
* What are the basic characteristics of the 5 classes of echinoderms?
* How do sea stars capture and ingest their prey?
* How do echinoderms in general locate their prey?
* What are the characteristics of the sea cucumbers?
* How do sea cucumbers repel predators?
* of what use is autotomization to ophiuroids?
* What are thought to be the causes of the disease known as "echinoderm blight"?
* What groups of crustaceans are "shrimp-like?"
* What is the main diet of copepods?
* Besides grazing on plankton, what other types of feeding are found in the copepods?
* Which groups of crustaceans are scavenger?
* How do female crustaceans care for their eggs?
* What is the settlement behavior of barnacles?
* Which crustaceans are abundant components of the demersal zooplankton?
* What group of crustaceans are vitally important to baleen whales?
* What is the food of most demersal shrimps?
* To what class do nearly all aquatic arthropods belong?
* What adaptation enables macruran crustaceans escape from predators?
* How do sand crabs capture their food?
* What must a hermit crab locate before it can molt and grow?
* What are the larval stages of crustaceans?
* How does the angle of the sandy beach influence the intertidal distribution of sand crabs?
* What does the carapace of crustaceans cover?
* Besides the tropics, where have demersal zooplankton been found to be abundant?
* What feature of the anatomy of a fish marks the division of the head and the thorax?
* What is the reproductive behavior of the deep-sea angler fish?
* How do pelagic sharks with heterocercal tails compensate for the direction of thrust of the tail?
* What are the sensor organs of pelagic sharks?
* How do bony fishes coordinate their schooling behavior?
* What fish is used by the fishes to produce the primary thrust for swimming?
* What structure covers the gill openings of fishes?
* How is the aspect ration of a fishes caudal fin calculated?
* What are the characteristics of a reef fish and a pelagic fish?
* How do fishes sense vibrations in the water?
* What is the pathway of water as a fish respires?
* What are the potential function of the gills of bony fishes?
* What are the limitations of the stiff pectoral fins of pelagic sharks?
* How do sharks partially compensate for lacking a swim bladder?
* What types of compounds of nitrogen are produced by bony fishes and cartilaginous fishes?
* What are denticles?
* How do the teachings of Plato give us insight into the process of science?
* What are the types of reproduction in fishes and how do the number and size of eggs differ?
* What are the advantages of the difference in the form of juveniles, females and males to the sheepshead fish?
* What are the adaptations of fishes to osmoregulate (water balance)?
* How do sting-rays and skates excavate the soft sediments to uncover their prey?
* Describe the eyes of deep water fishes that do not migrate vertically?
* Why are some fishes brightly colored and others camouflaged?
* How dos fishes suspension feed?
* What are the three classes of vertebrates included in the study of ichthyology and what are their distinguishing characteristics?
* What basic pigmentation pattern is common to nearly all fishes?
* How do bony fishes conserve water?
* What is the function of the mucous secretions of fish?
* What are the basic body forms of the cartilaginous fishes?
* What is the direction of thrust of the different types of caudal fins of the bony and cartilaginous fishes?
* What is the nature of the defense of a sting-ray fish?
* What is an anadromous fish?
* According to Greenwood, what features define a fish?
* What body form and lateral fin size would you expect of a fish who lives on a reef?
* What organ is responsible for the buoyancy of bony fishes?
* How does the number and size of eggs of broadcast spawning fish differ from viviparous fishes?
* What is the significance of the gape-and-suck mouth of fishes?