What is the best definition of directional selection

Why doesn't the stomach digest itself? a. the stomach wall is not composed of protein, so it is not affected by proteolytic enzymes. b. the digestive enzymes of the stomach are not strong enough to digest the stomach wall. c.

Many species of animals are common resources, and many must be protected by law to keep them from extinction. Why is the cow not one of these endangered species even though there is such a high demand for beef?

What is a hypothesis? A. a statement that can be tested through a scientific investigation B. a statement that summarizes the results of an experiment C. a question that cannot be scientifically tested D.

Which best describes binary fission--one way bacteria can reproduce? a. an exchange of genetic material between two bacterial cells through a special pilus b. a bacterium dividing in half c. a female bacterium mates with a male bacterium d.

Which process removes CO2 from the environment

Name classification of matter used in 1800

A key difference between hormonal regulation of the reproductive systems of males and females is that:

Which is the best evidence of an evolutionary relationship between two organisms?

Mt. Aconcagu is the highest peak of which range

Members of Porifera are diploblastic. Which statement clarifies this? A. They are unsegmented. B. They have a true body cavity. C. They have two germ layers.