Which type of molecule makes up the double layer of a cell membrane?
a) carbohydrate
b) lipid
c) nucleic acid
d) protein

The large ground finch obtains food by cracking seeds. what is its short, strong beak an example? a) tendency toward perfection b) adaptation of a species over time c) selective use and disuse of an organ over time d) scarcity of recourses

Darrel conducted an experiment with the following procedure: fill two cups with ice water. place an uninflated balloon snuggly onto your left index finger. blow a little air into an identical balloon, and place it onto your right index finger. place both fingers into the cups of ice water. darrel noticed that his right finger felt warmer in the ice water than did his left finger. which of the following does the experiment show? a. air is a good radiator of heat. b. air is a good insulator of heat. c. air is a good conductor of heat. d. air is a good convector of heat.

In what part of the body does the most muscle activity happen?