Answer:
D.
Explanation:
the term natural selection is how evolution takes place
Answer:
The process of making a copy of gene is called DNA replication.
Explanation:
This is a four step process. In first step, the DNA molecule which is double helical structure is unzip. This is carried out by enzyme called helicase which is also called biological scissors. Then after that DNA form Y like structure having complementary base pairs. Two strands are formed ; leading strand and lagging strands. They complementary base pairs allow the formation of new strands with help of primer. So new strand is then a copy of gene or called replicated strand.
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.
You would have to teach Desean appropriate social skills.
