1.Operons with an active repressor need to be turned ON/OFF (circle choice). 2.Transcription is normally ON/OFF (circle choice). Transcription is normally Blocked
3.When would it be beneficial for bacteria to produce enzymes to digest lactose?

1.Operons with an inactive repressor need to be turned ON/OFF (circle choice).
2.Transcription is normally ON/OFF (circle choice). Transcription is normally Occurring.
3.When would this be beneficial for a cell to have an operon whose Default position is on?
4.When would it be beneficial for the bacteria to NOT produce enzymes that make tryptophan?

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

The cluster of developing cells from conception until birth is called an

How does the diagram explain ocean currents? earth tilt 23.5 degreesquestion 1 options: earth's tilt causes uneven heating of earth which causes currents.earth's tilt causes the ocean to move because of gravity.earth's tilt and its rotation cause currents.earth's tilt causes uneven distribution of salt which causes currents.