Directions: Imagine that you could use a powerful microscope to observe each of the
following objects and materials. The
microscope allows you to see evidence of
cellular structure. Sort each of the objects and
materials into two categories: Not made up of
cells (never made up of cells) OR Made up of cells (or was once made up of cells).

After sorting each of the objects, explain your
thinking. In your explanation, describe any
rules, or factors you used to decide whether
something was made up of cells or not. Include thoughts of your group members as
well, even if you disagree with their approach.

An atom of nitrogen had seven protons in its nucleus. how many electrons does it have

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?

Which of the following is not a possible effectof increasimg carbon dioxide levels in the atmosphere ?