One student group hypothesized that the dry baker's yeast must be alive. the temperature change, odor, and bubble formation, they said, indicated which characteristic of life? a) be made of one or more cells b) detect and respond to select external stimuli c) have some form of nucleic acid as the hereditary molecule d) show growth and development; that is, specialization of cells or structures

The correct answer is option B, that is, detect and respond to select external stimuli.

Explanation:

The changing odor, temperature, and formation of bubble all suggest that the yeast is reacting towards the external stimuli. This is a feature of all living species. They will react towards the modifications taking place in their surroundings. The modifications that take place here as a consequence of the yeast utilizing the yeast in the dough in order to carry out the process of respiration.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.