Describe the most common tail fin modifications and discuss the ...

[sheilaspns]

Describe the most common tail fin modifications and discuss the swimming styles associated with each fin modification.
 
  What will be an ideal response?

Question 2

Which of the following is not considered paleoclimatological proxy data?
 
  A) Cave deposits
  B) Fossil pollen
  C) Reversed magnetic polarity
  D) Sea floor sediments
  E) Tree-growth rings

[shayla]

Answer to Question 1

Rounded fins are flexible and useful in accelerating and maneuvering at slow speeds. Truncate fins and forked fins are found on faster fish; the fins are somewhat flexible for better propulsion but are also used for maneuvering. Lunate fins are found on fast-cruising fish such as tuna, marlin, and swordfish; the fins are very rigid and useless for maneuverability but very efficient for propulsion. Heterocercal fins are asymmetrical, with most of their mass and surface area in the upper lobe. Sharks have a heterocercal fin, which produces significant lift and is necessary because sharks have no swim bladder and tend to sink when they stop moving.

Answer to Question 2

C

[sheilaspns]

Excellent

[Jsherida]

Gracias!