Evidence gathered by studying the composition and movement of distant galaxies indicates that the universe expanded rapidly from a single small point. The universe has continued to expand for over 13 billion years. Which statement is in agreement with the current understanding of the expanding universe?

A. All matter and energy were contained inside the small point.

B.)Matter and energy came from dark areas of the universe and were attracted to the small point.

C.)Matter and energy fell into the small point the same way a black hole attracts matter and energy.

D.)Matter was condensed into a single point until energy was attracted to the matter from dark areas of the universe.

1. environmental factors, such as ph and temperature, can affect the function of an enzyme. a. true b. false 2. which of the following is an organic molecules (ex. vitamins) that an enzyme? a. coenzyme b. product c. active site d. substrate 3. how do enzymes effect the speed of a chemical reaction? a. they speed it up b. they slow it down c. they have no effect on the speed of a reaction 4. during a chemical reaction, an enzyme is used up so that it can only be used one time. a. true b. false 5. which of the following results from a chemical reaction that is catalyzed by an enzymes? a. active site b. product c. substrate d. coenzyme

For a comparative or experimental investigation, scientists often make a testable about a scientific question, and then they test it in the investigation. a. control b. hypothesis c. procedure d. system

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?