Transcription factors are necessary for an initiation of transcription at a regulated gene but not sufficient.
Transcription is the first step of gene expression in which DNA molecule is copied (transcribed) into RNA (mRNA) by RNA polymerase. The process of transcription is divided into three phases:
1. Initiation
• RNA polymerase with transcriptional factors bind to gene promoter Transcription factors can enhance the interaction between RNA polymerase and a DNA sequence- promoter, encouraging the expression of the gene. Such transcription factors are called activators. Otherwise, when the gene expression is inhibited, factors are called repressors and they bind to sequence –operator.
• RNA polymerase unwinds DNA double helix (transcription bubble is formed)
2. Elongation
• RNA polymerases adds nucleotides complementary to DNA
3. Termination
• RNA polymerase gets to stop codon (transcribes a sequence of DNA known as a terminator)
• Formed complementary RNA strand is released from DNA-RNA complex
Food moves through the digestive system tract by peristalsis, which is produced by wavelike contractions of INVOLUNTARY muscles
The recombinant offsprings are normally the offsprings containing a combination of the parents allele, result in a genotype that differs from both parents genotype. The phenotype May be different as well although it is likely that the phenotype could be the same as the parents, as seen in the case of heterozygous dominant having the same phenotype as homozygous dominant.
Answer:
Exposition is a text that elaborates the writer‘s idea about the phenomenon surrounding. Its social function is to persuade the reader that the idea is important matter.
Explanation:
