In transcription: select one:
a. several amino acids are assembled by the messenger rna molecules at one time.
b. a special sequence called a promoter is necessary for transcription to begin.
c. certain polypeptide sequences are governed by one ribosome, while other sequences are produced by other ribosomes.
d. the transfer rna molecules arrange the messenger rna codons into the appropriate sequence.
e. none of these.

Option (b).

Explanation:

Transcription is the process of formation of RNA molecule from the DNA with the help of enzymes and proteins. The transcription always occur in the 5' to 3' direction.

Transcription involves three steps- initiation, elongation and termination. The initiation of the transcription requires the special nucleotide sequence known as promoter. This sequence are the conserved sequences and RNA polymerase binds at this site.

Thus, the correct answer is option (b).

explanation:

venn diagram is pictorial representation with of circles showing the relation between two finite sets or things. the intersection part of two circles conveys the relation present in between those sets or things.

here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.