/31/2018 11:55 PM 21.6/35 Grade Print Calculator Print CalculatorPeriodic Table
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/31/2018 11:55 PM 21.6/35 Grade Print Calculator Print CalculatorPeriodic Table uestion 28 of Genetics: A Conceptual Approach Reading Qui MHE/Freeman Map What is epigenetics? chemical chanpes such as DNA methylation that alter the nucleotide sequence but not the O overall packaging of the DNA mechanisms by which changes in maintained across numerous cell divisions occur within a cell but are unable to be changes that occur within the nucleotide sequence of noncoding regions but still have the O ability to cause a change in phenotype and be passed to future generations chemical modifications such as histone acetylation that impact the structure of chromatin but do o case a change in phenotype mechanisms by which changes in phenotype are maintained in a cell or are passed to other O cells or future generations without a change in the base sequence of DNA 2 6 8Explanation / Answer
Mechanisms by which changes in phenotype are maintained in a cell or are passed to other cells or future generations without a change in the base sequence of DNA.
Epigenetics is the study of heritable changes in gene function that do not involve changes in the DNA sequence.
Epigenetics most often denotes changes in a chromosome that affect gene activity and expression, but can also be used to describe any heritable phenotypic change that does not derive from a modification of the genome, such as prions. Such effects on cellular and physiological phenotypic traits may result from external or environmental factors, or be part of normal developmental program. The standard definition of epigenetics requires these alterations to be heritable,either in the progeny of cells or of organisms.
The term also refers to the changes themselves: functionally relevant changes to the genome that do not involve a change in the nucleotide sequence.
Examples of mechanisms that produce such changes are DNA methylation and histone modification, each of which alters how genes are expressed without altering the underlying DNA sequence. Gene expression can be controlled through the action of repressor proteins that attach to silencer regions of the DNA. These epigenetic changes may last through cell divisions for the duration of the cell's life, and may also last for multiple generations even though they do not involve changes in the underlying DNA sequence of the organism, instead, non-genetic factors cause the organism's genes to behave (or "express themselves") differently.
Most epigenetic changes only occur within the course of one individual organism's lifetime; however, these epigenetic changes can be transmitted to the organism's offspring through a process called transgenerational epigenetic inheritance. Moreover, if gene inactivation occurs in a sperm or egg cell that results in fertilization, this epigenetic modification may also be transferred to the next generation.
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