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
Answer:
D
Explanation:
The simple answer is the electrons in the outermost energy level.
Hydrogen has 1 electron in the outermost energy level.
Magnesium has 2 so this tells you that magnesium has a charge of 2
Oxygen has 6 oxygen has a charge of - 2
Fluorine has 7
For most elements, the electrons in the most outer ring determine the valence of the element.
Notice that the non metals work differently than the metals. Mg may have a charge of 2 and that is the number of electrons in the valence right.
Oxygen is a non metal it has a charge of - 2. It gets 6 electrons by subtracting the number of its charge from 8.
<span> Analyze what could have happened, and change the experimental methods to retest the hypotheses in a different way.. </span>
