Answer:
C) Through genomic imprinting, methylation regulates expression of the paternal copy of the gene in the brain.
Explanation:
The pattern of gene expression wherein either paternal or maternal gene is expressed in specific cells while the other one is prevented from expression is known as genomic imprinting.
In the given example, the maternal copy of the gene on chromosome 15 is expressed in brain cells while its paternal copy is not expressed in these cells. Hence, the pattern of expression of this gene is regulated through genome imprinting. One of the mechanism is methylation of cytidine residues of CpG islands of the DNA that are more frequently present within promoters of the genes.
When the cytidine residues of these sequences are methylated into 5-methylcytidine, the transcription factors do not bind to these promoters preventing the expression of these genes.
Hence, methylation of cytidine residue in CpG islands of the promoters of the gene present on chromosome 15 could have silenced its expression in brain cells.
Answer:
B. High temperatures
Explanation:
the canopy of the forest cover the rest of the forest, so it is cooler
The answer is C or B.
If it was permeable water and other substances could get through.
And hard? That is one of those answer choices teachers throw in to try and make an obvious elimination choice.
I hope I have helped!
<h2>Answer:</h2>
The mRNA is important for carrying the sequence information of amino acid in poly peptide chain. While tRNA carry the specific amino acids from cytoplasm to the poly peptide chain according to the message in mRNA.
<h3>Explanation:</h3>
- mRNA is the message from the DNA in the form of specific nucleotide sequence.
- mRNA is complementary sequence of nucleotide formed in the process of transcription in nucleus.
- While tRNA are also produced in the nucleus from the DNA but they do not contain any message for the poly peptide production. While they are transported to cytoplasm and their function is the transport of amino acid from cytoplasm to growing poly peptide chain.
