Science Assessment

A hen lays a fertilized egg that will develop into a chick. The egg shell has tiny holes in it that allow gases to enter and leave the egg. (For these questions, assume that oxygen, carbon dioxide, and water vapor are the only gases that enter and leave the egg). The yolk inside the egg is a source of energy and building materials for the growing chick. Therefore, as the chick grows bigger, the yolk gets smaller.

As the chick grows, what role do oxygen and carbon dioxide play in the chick’s growth?

1. Oxygen enters through the egg’s shell. Inside the egg, oxygen is used by the chick as a source of energy and is turned into carbon dioxide. The carbon dioxide then leaves through the egg’s shell.
2. Oxygen enters through the egg’s shell. Inside the egg, oxygen reacts with molecules from the yolk to release energy for the growth of the chick. This reaction produces carbon dioxide that then leaves through the egg’s shell.
3. Oxygen enters through the egg’s shell. Inside the egg, oxygen reacts with molecules from the yolk to release energy for the growth of the chick. Carbon dioxide can enter and leave through the egg’s shell, but it does not play a role in the chick’s growth.
4. Inside the egg, molecules from the yolk are turned into energy for the growth of the chick. This conversion produces carbon dioxide that leaves the egg. Oxygen can enter and leave through the egg’s shell, but it does not play a role in the chick’s growth.