Question

Whales in the order Odontoceti are smaller than whales in order Mysteceti. Which of the following best explains this?

Answer 1

A. whales in order Mysteceti are filter feeders and obtain lower levels of energy by consuming krill, zooplankton, and small fish.

B. whales in order Mysteceti are toothed and therefore are high level predators and obtain higher levels of energy by consuming large fish, squid, and seals.

C. whales in order Odontoceti are filter feeders and obtain higher levels of energy by consuming krill, zooplankton, and small fish.

D. whales in order Odontoceti are toothed and therefore are high level predators and obtain lower levels of energy by consuming large fish, squid, and seals.

Answer 2

First find out which order of whales is toothed.
http://cetacea147.tripod.com/odontoceti.html

I believe the real reason for the smaller size if because they need agility to be able to hunt.
In comparison, think of which vehicle will win a race in city streets between a small car and a large trailer truck. The energy level depends on the quantity and type of food they consume.

and read more about toothed whales
http://animals.about.com/od/cetaceans/p/toothed-whales.htm