A mistake in DNA replication before meiosis produces an organism that is better able to outrun predators.
Explanation:
The genetic variation results from the different alleles of a population. The mutation or mistake in DNA replication would cause gene variants which may be beneficial. The variation in the DNA sequence of genome results in variants in small population.
Genetic variation is the cause of natural selection and eventually, evolution takes place with beneficial traits.
It is mentioned in the question that resulting offspring having received the mutant allele could result in better surviving capabilities or phenotypic traits as they are able to outrun predators.
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.
I believe the answer is protein
