2. Surface Area, Volume, and Life

What is the surface area to volume ratio of the cube?

• 1

• 1.5

• .66

• 6

Consider two spherical (ball-shaped) cells. One is 150 micrometers in diameter while the other has a diameter of 300 micrometers. Which has the greater surface area-to-volume ratio?

• The smaller diameter cell

• The larger diameter cell

• They have the same surface area-to-volume ratio

Which of the following best describes why cells are small?

• Cells do not have enough DNA to allow them to grow very large.

• Cells have only enough resources to grow to a certain size and then they have to stop growing.

• As cells grow larger, their surface area-to-volume ratio decreases, and they are no longer able to receive nutrients and remove wastes in a timely matter.

• The size of the cell is directly related to the size of the organism, so smaller organisms have smaller cells, and larger organisms have larger cells.

What would happen to an elephant with very tiny ears?

• Heat would exit its body quickly, and the elephant could die.

• It would take too long for heat to exit its body, enzymes would denature, and the elephant could die.

• Its body would cool quickly, enzymes would not function efficiently, and the elephant could die.

• It could not locate its food source.

When cold, how do humans decrease their surface area to volume ratio?

• They hold their arms away from their body, decreasing heat loss.

• They straighten their legs, decreasing heat loss.

• They fold their arms tight against their body, decreasing heat loss.

• They sweat

Why do the villi of the small intestine have a wavy shape?

• A wavy shape decreases the surface area to volume ratio, allowing more nutrients to be absorbed.

• A wavy shape increases the surface area to volume ratio, allowing more nutrients to be absorbed.

• A wavy shape increases the surface area to volume ratio, allowing less nutrients to be absorbed.

• A wavy shape decreases the surface area to volume ratio, allowing less nutrients to be absorbed.