Which levels of protein structure are expected to be altered as a result of the amino acid substitutions? 1. primary structure
2. secondary structure
3. tertiary structure
4. quaternary structure

Spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

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?

Identify the composition of oceanic and continental crystal rocks. in a model of earth’s interior, where would these rocks appear?