Which of the following statements does not accurately complete this statement: An epigenetic trait _________.can be passed from mother cell to daughter cell by mitosiscan be passed to the next generation by meiosisis a change in the DNA sequencecauses changes in gene expressionAll are accurate Of the following, which is a good example of epigenetic changes?methylation of DNA basesaddition of acetyl groups to histonesCpG islandsimprinting of genesAll are good examples of epigenetic changes

Introduction Gene expression during the developmental phase can be regulated by several factors which can control the phenotype of the offspring. Epigenetics deals with the regulation of phenotype of the species without having change in the sequence of DNA. Epigenetics helps us in understanding of various factors which can influence the phenotype and development of any disease such as cancer. In the Epigenetic, gene expression can be controlled by DNA methylation, acetylation, histone modifications etc. Any of these modifications doesn’t lead to change in DNA sequence still manage to control the expression of gene. Methylation Acetylation Phosphorylation etc.All these modifications are catalysed by various enzymes such as HAT (Histone acetyl transferase) HMT (histone methyl transferase) etc. Methylation: DNA methylation can switch off the activity of gene temporarily, By DNA methylation Euchromatin (transcriptionally active) can be turned into Heterochromatin (transcriptionally inactive). During this modification methyl group is added to some specific amino acids of histone proteins. Histone methylation causes repression in the gene expression and convert the euchromatin region into heterochromatin which readily interchangeable. Acetylation: In histone acetylation, acetyl group is transferred to the amino acids of histone proteins such as H3K9 (histone protein H3, on lysine number 9), H3K4 etc. this is catalysed by histone acetyl transferase, this is also readily interchangeable and the removal of acetyl group is catalysed by histone deacetylase enzyme. Unlike methylation, histone acetylation however can sometime cause repression or activation of gene expression based on the amino acids involved in the process. Phosphorylation, however can have both the effects, but usually it promotes the gene expression. Genomic imprinting is referred as epigenetic process which involves DNA methylation, histone modification etc. without changing the genomic sequence. It is an inheritance process which is independent from classical Mendelian inheritance. Imprinting of genes is important phenomenon for development process, and abnormal genomic imprinting can cause various disorders such as Angelman Syndrome etc. CpG islands are nothing but the specialized regions of DNA sequence which are highly methylated. Here, C and G nucleotide bases are methylated and these regions are generally transcriptionally inactive and considered as the part of Heterochromatin. As the statement that epigenetic is due to the change in DNA sequence is wrong, Hence, option 3) is correct answer for 1st question. As epigenetic is consisting of methylation, acetylation, CpG island and gene imprinting therefore, all these statements are correct. Hence, option 5) is correct answer for 2nd question.