A scientist observes that when she opens the back door of her house to let her cat out, the songs of a certain species of bird abruptly change.  She wants to follow up on her observations with an informal experiment.  Which of the following is the best hypothesis for explaining the birds’ song changes?

How did the hydrocarbons found in petroleum products such as gasoline get their energy?

Why are amino acids called “amino acids?”

The disease called sickle-cell anemia is caused by a change in a single amino acid residue in the hemoglobin protein, resulting in a distortion of the protein’s shape at which levels?

What is the major component of the plant cell wall?

A biologist isolates a large, unidentified molecule from some cells in his lab.  What type of reaction could he initiate to determine whether the molecule is a polymer and, thus, a macromolecule?

Why does heating up a protein such as an enzyme cause it to lose function?

Which of the following is true of the influenza strain that struck the world in 1919?

Answer this question in Spanish in 3 complete sentences.   ¿Hiciste ejercicio esta semana?  Explica.

Identify the infinitive from module 3 that is linked to the following description. Write all lower case, with no punctuation.  el gimnasio, los músculos grandes, el ejercicio, las pesas