Answer:
An amino acid activates the repressor so that the repressor binds to the operator and prevents transcription.
Explanation:
In an operon, promoter is followed by operator which is finally followed by the structural genes to be transcribed. RNA Polymerase binds to the promoter and initiates transcription. A repressor can negatively control the transcription process by binding to the operator so that the RNA Polymerase is not able to move forward and transcription is halted.
For example: in trp operon, tryptophan amino acid binds to the repressor molecule which leads to change in repressor's shape. The repressor is now able to bind to the operator and prevent transcription.
<span>B is the correct answer. The beginning of DNA replication occurs with the unwinding of the DNA helix by a special enzyme. The two strands that form the helix then create a replication fork. The two strands are then oriented differently, one becoming the 'leading strand' and one the 'lagging strand'. </span>
Biosphere because humans and animals live
Answer:
Seminal vesicle secretion is important for semen coagulation and may promote sperm motility, increase stability of sperm chromatin, and suppress the immune activity in the female reproductive tract.
Explanation:
Copy and paste the paragraph into Google, and you will get an article on the topic.
Spirilla bacteria are Gram-negative bacteria that may cause bacterial diarrhea, adenocarcinoma and peptic ulcers.
