The minimum length for this assignment is 2,000 words. Be sure to check your Tur

Question

The minimum length for this assignment is 2,000 words. Be sure to check your Turnitin report for your post and to make corrections before the deadline of 11:59 pm Mountain Time of the due date to avoid lack of originality problems in your work.

Discoveries in DNA, cell biology, evolution, and biotechnology have been among the major achievements in biology over the past 200 years with accelerated discoveries and insights over the last 50 years. Consider the progress we have made in these areas of human knowledge. Present at least three of the discoveries you find to be most important and describe their significance to society, health, and the culture of modern life.

Explanation / Answer

1). Discovery of DNA structure:

The X-ray photographs of DNA were took by the British scientists Rosalind Franklin and Maurice Wilkins in 1950s. It showed the helical shape of DNA. Later Chargaff proposed that, in a double stranded DNA (deoxyribonucleic acid), the ratio of purines to pyrimidines is always 1: 1 (complementary pairing). Means, the percent of adenine is equal to thymine and the percent of guanine is equal to cytosine.

During the same time, the British scientists Watson and Crick were also trying to determine the DNAs structure. After several attempts that did not work, they saw the Franklin’s photographs and created a new DNA model. In this new model is, strands of a double helix, which appears like a spiral staircase. Finally, they published their results in 1953.

During cell division, the replication of DNA occurs, which is nothing but duplication of chromosomes. DNA replication results in the formation of two new DNA helices. As the structure of DNA is double helical and the nitrogen bases bind complementary to each other, scientists assumed that DNA replication is semiconservative. Means, one of the DNA strand serves as a template and the complementary bases add to the template, forming a new double helical DNA. The semiconservative pattern of DNA replication is demonstrated by Meselson and Stahl.

The DNA structure determination played a key role in understanding the functioning of genes, cell growth, and evolutionary studies.

2). The discovery of recombinant gene technology or genetc engineering: It was discovered by Herbert Boyer and Stanley Cohen in 1972. “Genetic engineering” is based on the recombinant DNA (deoxyribonucleic acid) technology, the modification of an organism’s genetic makeup, which results in the modification of its phenotype. A selected gene is modified and reinserted into a plant cell of the same species or a gene from an individual of one species is inserted into another species by using several gene transfer techniques like microinjection, liposome fusion, electroporation, or else using chemicals like polyethylene-glycol. Now these inserted cells have to grown in a plant tissue culture media. Now the resulting one is a “transgenic plant” in either of the cases.

Genetically modified organisms/foods are those whose gene profile is altered by genetic engineering techniques. The purpose of gene modification is to increase the yield of either plants or animals.

Some of the people are against genetic engineering because of the reason that using the genetically modified organisms alters the biodiversity and negatively affect the environment. This might be the reason why Vandals wanted to destroy the strawberry crop in 1987.

3). The human genome project:

Human Genome Project (HGP) is one of the biggest genome projects completed. In this project, the whole human genome is sequenced to identify all the genes. From the data interpreted till now, it was concluded that humans share some set of genes with all other species.

Also, humans contain certain unique set of genes that are necessary for intellectual functioning and the other unique characteristic of humans. However, sharing the genome with the all other species indicates that all living organisms arose from a common ancestor.

The applications of completing the Human Genome Project are,

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