It will all make more sense if you start from the beginning of the sequence with the structure of DNA. You will remember that messenger RNA contains a sequence of bases which, read three at a time, code for the amino acids used to make protein chains. Each of the sets of three bases is known as a codon.
<span>(According to Reference)
Whereas an onion epidermal cell has a cell wall, a human cheek cell does not. Instead, a semi-permeable membrane surrounds the cytoplasm of the cheek cell. While there are chloroplasts present in onion cells, they are absent in cheek cells. </span>
Answer:
An Enhancer
Explanation:
Enhancers are the regulatory sequences and are generally located 80-160 base pairs upstream of the transcription start site. Enhancers have bidirectional elements that are involved in the initiation of transcription. Enhancers serve as the binding sites for activators to increase the concentration of activators in the vicinity of the promoter and thereby increase the rate of transcription of the gene.
According to the given information, the loss of a regulatory sequence led to a reduced level of transcription of the gene. This means that the regulatory sequence was involved in the upregulation of transcription. The presence of the sequence far away from the promoter makes it an enhancer.
"Denatures" is the word you are looking for!
