If lactose is present, would the lac operon in bacterial cell be on or off? Explain

Explanation:

The lac operon

When lactose is present, bacteria need the enzymes to break it down. But if no lactose is present, bacteria do not need to waste resources making enzymes to break down a sugar that isn't there. Like a switch, the operon is turned on when the enzymes are needed.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.