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:
Structurally, plant and animal cells are very similar because they are both eukaryotic cells. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes. Both also contain similar membranes, cytosol, and cytoskeletal elements.
Explanation:
DNA, which is a sequence of nucleotides, make up genes. Genes are DNA sequences that code of a functional protein and are controlled by a promoter region on the DNA. DNA, including genes within it, are supercoiled into chromosomes so they are able to fit in the cell. Otherwise, uncoiled DNA in a cell is much longer than the cell itself.
The answer is dominant.
A monohybrid cross involves organisms that are heterozygous for only one character. In autosomal dominant traits, the phenotype is present if both copies of the dominant allele (A) are present (homozygous individuals AA) or only one copy of the dominant allele is present (heterozygous individuals Aa). <u>Thus, t</u><span><u>he characteristic that results from a monohybrid cross is the dominant trait.</u></span>
