Genes and Environment - Research Paper Example

 “Genes and Environment” Introduction Genes are the basic unit or molecular structure of heredity that is present in all living organisms irrespective of their size, shape and habitat. The ability of living organisms to grow, reproduce and proliferate depends on a vast number of chemical reactions which are directed and controlled by these entities called genes. Chemically genes comprise of the DNA or de-oxy-ribonucleic acid and RNA or he ribonucleic acid. These are called the genetic material of the cell and are made up of nitrogen base, a pentose sugar and the phosphate molecule. DNA is double helix structure while the RNA is a single helix structure in a normal cell. DNA is present on the chromosomes in a coiled helical manner and controls the cellular metabolism as it has nitrogen base that contain four different nitrogen bases- Adenine (A), Guanine (G), Cytosine (C), Thymine (T). A pairs with T with a double Hydrogen bond while G pairs with C with a triple nitrogen bond. On the other hand RNA also contains A, G, and C but instead of T it has U, the Uracil. Exact sequence of the base pair is required for the formation of a particular protein any change in the sequence of the base pairs changes the structure and function of the protein molecule and hence the cellular metabolism is affected (Alberts, 2002; Snustad, 2002). DNA controls the cellular environment as well as the metabolic processes, synthesizes m-RNA molecule by the process of transcription, RNA in turn synthesize polypeptide chain by the process of translation. Polypeptides are the basic structure of the protein molecules. These proteins are responsible for the formation of enzymes which control the cellular mechanism and hence influence the organisms survival (Alberts, 2002; Snustad, 2002). Genes possess information to maintain the cellular environment and trigger the formation or stoppage of the formation of polypeptide. Depending on the cellular requirement the genes are switched on and off. Genes are the heritable units i.e. they pass the genetic traits to the offspring. The genetic makeup of the organism is called the genotype while genes also govern the external appearance of the organism, the phenotype. It is because of genes an offspring resembles parents in appearance and behaviour to certain extent. Thus, genes are the most vital components of life and carryout all the biological processes (Alberts, 2002; Snustad, 2002). Number of genes vary from organisms to organisms. For instance, micro-organisms possess single chromosomes and therefore they have limited genes. Viruses, which are the considered to be the connecting link between the living and non-living entities carry either DNA or RNA. For their replication and multiplication they pass only the genetic material to the host cell and this genetic material takes control over the host cell machinery to make multiple copies of the viral particles. Thereby highlighting the fact that genes retain all the information required for the formation of the complete organism, from single cell to multicellular organisms (Alberts, 2002; Snustad, 2002). Multicellular organisms possess greater number of chromosomes for instance, human beings have 23 pairs of chromosomes carrying different genes located on different chromosomes to carryout different physiological and biological processes (Alberts, 2002; Snustad, 2002). Interaction of genes As genes are chemical entities, they are liable to interact with various physical and chemical molecules. These chemicals interact with the genetic molecules and potentially alters their characteristics. Alteration of genes is called mutation (Alberts, 2002; Snustad, 2002). Alteration of genes occur in many ways either in terms of addition, deletion, duplication of base pairs. These alterations are responsible for various genetic anomalies. Genetic anomalies occur when the normal synthesis of the protein molecule is altered leading to the formation of faulty protein which either hampers the metabolic pathway or alters the external appearance of the organism. This alteration may be beneficial or detrimental for the organism. Enhancement of characteristics may result in providing benefit which is exploited by various researchers to enhance the crop yield or to improve the characteristics of animals. Interaction of UV radiation with the skin results in the skin cancer (Alberts, 2002; Snustad, 2002). Genes are the sole responsible entities to interact with the environment of the organism and respond to it. They are responsible for triggering the formation of antibodies when there is an attack by the bacteria or any other agent that elicits a change in the cellular environment. Depending upon the interaction, diseases are caused. Thus, alteration in the genetic makeup of the organism is responsible for the changes in organism. For instance, if three copies of the 21st chromosomes are present due to non-disjunction of the chromosome it results in the genetic anomaly called Down's Syndrome. In a similar manner if the HIV virus takes control of the cellular DNA molecule then it results in a condition called AIDS. By triggering the proto-oncogenes due to certain environmental factors, it is converted to oncogenes which is responsible for causing cancer of that particular organ (Irigaray et al, 2007). Considering genes as of paramount significance to bring about the alteration in the cellular environment or the environment of the organism, researchers have started manipulating genes to draw benefit from them for therapeutics, drug manufacturing, to enhance crop yield, to generate resistant variety of seeds to prevent the crop from damage caused by the insects and pests. Gene therapy is gaining prevalence to treat various genetic anomalies by providing the synthetic gene that is manufactured in laboratory to cure the condition. Various genetically modified plants and animals are being generated for better taste, higher yield and for better production to increase the production of food items to meet the escalating demands of rising population. This is done by artificial selection and manipulation of genes (Alberts, 2002; Snustad, 2002). Thus, nature of an organism is directly influenced by the genes while the nurture is influenced by the environment of the organism. This interaction is solely responsible for the well being of the organism. Changes in the environment encompassing the climatic condition, the quality of food consumed, exposure to physical and chemical agents alters the genetic makeup and hence the entire biological machinery is disturbed. Exposure to certain agents which are called carcinogens may result in the cancer while exposure of fetus to teratogenic agents may result in the birth defects. On the other hand, manipulation of genes is responsible to cure various disease conditions to improve life of the inhabitants both from the plant world and also from the animal world. These manipulations are performed by exploiting the beneficial characteristics of one organisms and expressing it in other to draw the benefit. Such interaction of genes in a new environment bring different results. Hence genetic interaction with the environment is diverse and is liable to bring both beneficial as well as devastating consequences (Genes and Environment). Reference Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K. and Walter P. "Molecular Biology of the Cell". 4th ed. Publisher Garland Science. 2002. "Genes and Environment" (Web.) 30 March 2012. . Irigaray, P., Newby, J. A., Clapp, R., Hardell, L., Howard, V., Montagnier, L., Epstein, S., Belpomme, D. "Lifestyle-related factors and environmental agents causing cancer: An overview". Biomedicine & Pharmacotherapy. 61(10). 640-658. 2007. Snustad, D.P., Simmons, M.J. "Principles of Genetics". 3rd ed. Publisher Wiley. 2002. Read More