Repressors
A. are involved in negative control.
B. are involved in positive control.
C. always bind to the promoter.
D. bind or do not bind to the operator depending on their shape (conformation).
E. are involved in negative control AND bind or do not bind to the operator depending on their shape (conformation).
E
You might also like to view...
In a PCR reaction, a few seconds at high temperature disrupts the ____ that hold the two strands of DNA together, so
every molecule of DNA unwinds and becomes single-stranded.
a. covalent bonds b. peptide bonds c. hydrogen bonds d. lipoproteins e. DNA ligases
El Niño and La Niña ____
a. both decrease water temperatures in the eastern Pacific Ocean b. both increase water temperatures in the eastern Pacific Ocean c. both increase water temperatures in the Gulf of Mexico d. cause more rain and less rain, respectively, in Australia e. cause fewer hurricanes and more hurricanes, respectively, in the North Atlantic
Birds belong to a related group of vertebrates that includes all of the
A) ray-finned fishes. B) amphibians. C) lobe-finned fishes. D) reptiles. E) mammals.
When DNA is heated to just below boiling (90°C-95°C),
A. the helix unwinds but hydrogen bonds between the bases remain intact. B. the sugar, phosphate, and base come apart in each nucleotide. C. the two DNA strands separate completely. D. nothing happens until the boiling point is reached (100°C). E. the sugar phosphate backbone of the DNA strands breaks.