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:
ribulose bisphosphate carboxylase (RuBisCO)
Explanation:
The Calvin cycle is a process utilized to ensure carbon dioxide fixation. ... The carbon dioxide is combined with ribulose 1,5-bisphosphate to form two 3-phosphoglycerate molecules (3-PG). The enzyme that catalyzes this specific reaction is ribulose bisphosphate carboxylase (RuBisCO).
Answer:
Option (1).
Explanation:
DNA (deoxyribo nucleic acid ) is the genetic material present in all the organisms except some viruses. DNA structure follows the Chargaff's rule.
Accoprding to Chargaff's rule, the ratio of purines to pyrimidines in a DNA molecule is equal to 1. The amount of guanine is nearly equal to the amount of cytosine whereas the amount of thymine is nearly equal to the amount of adenine.
Thus, the correct answer is option (1).
