Epigenetics and Heredity: YR 12 Biology Assessment Extended Response

This essay examines the field of epigenetics and its impact on our understanding of heredity. It begins by defining epigenetics and differentiating it from traditional genetics, emphasizing the role of gene expression control rather than alterations to the DNA sequence itself. The essay explores the relationship between DNA, gene coding, protein synthesis, and mutations, highlighting how epigenetic changes can modify gene activation and lead to altered protein formation. It then delves into how the theory of epigenetics extends our understanding of inheritance, challenging the conventional view that inheritance occurs solely through DNA code transmission. The essay analyzes the implications of epigenetics for society, discussing how environmental factors and lifestyle choices can influence health outcomes across generations. Two case studies, including the effects of maternal smoking and nutritional intake during pregnancy, are presented to support the epigenetic theory. The essay concludes by emphasizing the significance of epigenetics in understanding the interplay between environment, lifestyle, and genetic function, and its potential for developing precision medicine and therapies.

Running head: EPIGENETICS
EPIGENETICS
Name of the Student:
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Author Note:

1EPIGENETICS
How does epigenetics impact on our present understanding of heredity?
Epigenetics can be defined as the segment of genetics that deals with the transmission
of heritable changes in subsequent generations and the associated impact of genetic
expression. In other words, epigenetics refers to comparison of the active genes versus the
inactive genes and how change within the DNA sequence can give rise to change in
phenotype with the overall genotype remaining intact (Norouzitallab et al., 2019). It should
be noted in this context that epigenetic change is a natural occurrence within the environment
and is influenced by the interplay of a number of factors that include influence of the external
environment, life style factors as well as the quality of the disease state. On a broader
perspective, it can be stated that epigenetic mechanisms that impact the manner in which cells
terminally differentiate into other cell types such as hepatic cells, brain cells or skin cells.
Research studies in this regard mention that the biochemical procedures of DNA methylation,
non-coding RNA associated gene silencing as well as histone modification help to sustain
epigenetic changes within a gene (Norouzitallab et al., 2019; Jadotte, 2019). Previously
researchers believed that the epigenome of a developing embryo is created freshly from the
initial phase. However, recent advancement in the field of epigenetics has revealed that some
of the epigenetic tags remain integrated and assist with the transmission of information from
one generation to another (Jadotte, 2019). It should be noted however that epigenetic
inheritance still remains an unconventional finding and opposes that idea that inheritance
occurs only through the transmission of DNA code that passes from the parent to the off
springs. In other words, recent scientific advancements have shown that epigenetic tags in the
form of parental experiences can be transmitted to subsequent generations. The epigenetic
basis of inheritance at present is not backed by substantial scientific research papers, however
the available evidence base appears to be promising and requires further investigation.

2EPIGENETICS
An understanding of DNA, gene coding, protein synthesis and mutations in relation to
epigenetics.
As stated by Ray (2019), the epigenetic code is hypothetically assumed to be a
definite code that is present within the eukaryotic cells and comprise of a particular
epigenetic conformation within respective cells. The epigenetic code comprises of modified
histones that are broadly defined by the codon coding for the histone protein and accessary
epigenetic modifications that give rise to the process of DNA methylation. It should be noted
in this context that the required base for the epigenetic coding system is strikingly different
when compared to the genetic coding system for a cell. The underlying basis of difference
can be explained as the presence of similar genetic code throughout every cell within the
body in case of the genetic code, whereas, the epigenetic code is tissue specific and varies
from one tissue to another (Burggren, 2016). Further, the epigenetic code can be
multidimensional and include any of three significant macromolecules such as the DNA,
RNA or the amino acid sequence.
Alteration of a genetic sequence can lead to a change of the phenotype and is
invariably referred to as mutation. Usually gene mutation has been believed to have occurred
on account of the impact of a mutagen that changes the genetic reading frame or the genetic
constitution of a gene and gives rise to impaired functions. In this regard it has been
mentioned that the epigenetic changes modify the extent of activation of a handful of genes
that might lead to silencing of genes and impact the functional protein formation. A range of
mutation mechanisms such as bookmarking, paramutation, gene silencing, X chromosome
inactivation. Position effect, transvection as well as methylation reprogramming lead to
impaired or affected protein synthesis (Mueller, 2019).

3EPIGENETICS
Further the transmission of epigenetic tag and associated impact on subsequent
generations reveal the pattern of epigenetic inheritance and continuity of generation.
How does the theory of epigenetics extend to the understanding of inheritance?
The epigenetic theory of inheritance suggests that the process of inheritance does not
occur independently on the basis of genetic code expression. The traditional method of the
biological pattern of inheritance is challenged by the invention of the trans-generational
epigenetic pattern of inheritance. The model suggests that environmental induced phenotypes
can persist for subsequent generations primarily on account of the transmission of molecular
factors that essentially determine the pattern in which the DNA sequence is interpreted and
expressed (Matheos & Wood, 2019; Mueller, 2019). In this regard, it should further be noted
that epigenetic regulation of genetic expression is a common process that impacts the process
of somatic cell differentiation in response to the environmental stresses and pass the modified
genetic function to the further off springs (Jadotte, 2019).
Present and analyse several implications for society that are associated with epigenetic
theory.
The field of epigenetics is rapidly emerging and is helping to estimate the relationship
between individual lifestyle, environment and coherent genetic functions. In this regard it can
be stated that epidemiological studies suggest that prenatal as well as post natal
environmental factors elevate the risk of developing a number of chronic health conditions
and behavioural disorders. A number of research studies have suggested that children that
were born during the time period of Dutch famine in between 1944-1945 were more likely to
suffer from coronary heart disease in their entire lifetime on account of maternal exposure to
famine during the pregnancy period (Matheos & Wood, 2019). In the same manner, extensive

4EPIGENETICS
research on the epigenetic theory can help to develop efficient precision medication and
therapy to improve positive health outcome.
Present and analyse two epigenetic case studies that support the epigenetic theory.
As per Knopik et al. (2012) it was mentioned that maternal cigarette smoking during
the period of pregnancy increased the risk of developing physical and behavioural disorders
in off springs. Further, the study also suggested that mothers that smoked during the
pregnancy were more susceptible to develop babies with reduced birth weight. In addition to
this a number of research studies have also indicated that lifestyle factors of parents and
grandparents such as nutritional intake were likely to impact child growth and development
(Marlor, 2019). A longitudinal study with 166 participants showed that starvation or over
eating during the slow period of pregnancy enhanced the off springs risk of developing
diabetes or coronary heart disease and alleviate the risk of premature death (Marlor, 2019).
These scientific case studies explain the impact of epigenetic on the genetic inheritance
pattern.

5EPIGENETICS
References:
Burggren, W. (2016). Epigenetic inheritance and its role in evolutionary biology: re-
evaluation and new perspectives. Biology, 5(2), 24.
Jadotte, Y. T. (2019). Epigenetics: The Process of Inheriting Health Disparities. In Social
Pathways to Health Vulnerability (pp. 143-156). Springer, Cham.
Knopik, V. S., Maccani, M. A., Francazio, S., & McGeary, J. E. (2012). The epigenetics of
maternal cigarette smoking during pregnancy and effects on child
development. Development and psychopathology, 24(4), 1377-1390.
Marlor, J. (2019). Science: Grandfather made me what I am. [online] Telegraph.co.uk.
Available at:
https://www.telegraph.co.uk/news/science/science-news/3312230/Science-
Grandfather-made-me-what-I-am.html [Accessed 21 Aug. 2019].
Matheos, D. P., & Wood, M. A. (2019). Extinction Versus Epigenetic Intergenerational
Inheritance: Who Wins?. Biological psychiatry, 85(3), 184-186.
Mueller, R. (2019, July). A Task that Remains Before Us: Reconsidering Inheritance as a
Biosocial Phenomenon. In Seminars in cell & developmental biology.
Norouzitallab, P., Baruah, K., Vanrompay, D., & Bossier, P. (2019). Can epigenetics translate
environmental cues into phenotypes?. Science of the Total Environment, 647, 1281-
1293.
Ray, L. B. (2016). Inheriting Mom's exercise regime. Science, 352(6284), 425-426.