1. Moves molecules from high to low concentration II. Moves molecules with the concentration gradient
III. Does not require energy
IV. Requires the use of a membrane protein
V. Used to move small and/or nonpolar molecules
VI. Used to move large and/or polar molecules
Cell membranes are selectively permeable, regulating which substances can pass through, as well as how much of each substance
can enter or exit at a given time. In cells, some molecules can move down their concentration gradients by crossing the
phospholipid portion of the membrane directly, while others must pass through membrane proteins. Which of these statements
does NOT apply to facilitated diffusion?

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?

Fungi are classified into how many groups? a. 1 group b. 2 groups c. 3 groups d. 4 groups

In an experiment examining the effects tai chi on arthritis pain, callahan (2010) selected a large sample of individuals with doctor-diagnosed arthritis. half of the participants immediately began a tai chi course and the other half (the control group) waited 8 weeks before beginning. at the end of 8 weeks, the individuals who had experienced tai chi had less arthritis pain that those who had not participated in the course.