Answer:
Option (A).
Explanation:
The lac operon system in bacteria elucidates the process of lactose metabolism within the cell. The initial operon system was identified by Jacob and Monod. An operon is characterized as a cluster of genes transcribed together as a single RNA unit.
When both glucose and lactose are available in the media, the bacterium favors metabolizing glucose. The presence of glucose is recognized by the bacterial cell as the CAP-cAMP complex is essential for transcription, and its levels are reduced in glucose's presence. This mechanism effectively halts the transcription of lactose genes even when lactose is available.
Consequently, the right answer is option (A).
A muscle cramp happens when a muscle contracts involuntarily and suddenly. Various factors can cause this, such as insufficient minerals like calcium or poor blood flow.
By straightening and vigorously massaging an athlete's leg, the muscle relaxes and returns to its normal position.
The liquid water, which is denser, provides better insulation against cold air for organisms than the less-dense ice.
