Year 10 Biology
Extended Response Task: Important Discoveries of Heredity
The research, experiments and discoveries scientists have made relating to genetics and DNA over the years has been vital to the current knowledge and understanding scientists have today. Deoxyribonucleic acid, or DNA, is a material that self-replicates and is present in almost every living organism. DNA is made up of two polynucleotide chains twisted together to form a double helix. These chains are held together by the complementary base pairs; which is the bonding between the four nitrogenous bases, adenine (A) and thymine (T), and guanine (G) and cytosine (C). It carries the genetic information needed for cell division, growth, and functioning. DNA is the unique genetic coding that is inherited from parent to offspring. Inheritance is the word used to describe traits which are genetically transmitted from parent to offspring.
Gregor Mendel, also known as the ‘father of modern genetics’, was an Austrian monk whose work was an extremely important contribution to the field of biology. It was Mendel who discovered the basic principles of heredity just by conducting experiments on pea plants in his monastery’s garden. Mendel’s experiments began around 1854, and by 1866 he had published his results. The results concluded information about genetic traits that were for a long time misunderstood. Mendel’s experiment showed that traits In pea plants were inherited in different genes.
Erwin Chargaff was an Austrian biochemist whose experiments showed that deoxyribonucleic acid (DNA), and not the amino acids in cells, is the carrier of genetic information. His work changed the study of biology and heredity completely, and provided the foundation for the work many sc...
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...ant to the field of genetics, as nobody had ever been able to find the structure of DNA previously.
The breakthroughs made by these scientists were extremely important to the world. If it weren’t for scientists such as Gregor Mendel, Rosalind Franklin, Erwin Chargaff, and James Watson and Francis Crick, the scientific knowledge we have now may not have even been discovered for many more years. The reason the field of genetics is so important is that it is the field in which so many health breakthroughs occur. Without the genetics field, the understanding of DNA, inheritance, and many more related things would be very vague. The future of genetics looks promising. The Cancer Genome Atlas has aimed to identify every genetic abnormality found in fifty of the major types of cancer. When something like that occurs it’s going to be a huge event in the field of genetics.
Genes are expected to give offspring hereditary similarities to the parent. However, this was not known and Gregory Mendel asked himself what was passed on by parents to their offspring that is the basis for similarity. Mendel would go on through experiments with pea plants to answer short questions. The answers were short as well as to say that the passing of characteristics from parents to the offspring is throug...
In 1953, Francis Crick bragged to his fellow colleagues from the Cavendish Laboratory (Cambridge), claiming that he and his American partner, James Watson, had “discovered the secret of life.” The claim, made in a bar over a glass of alcohol, was not unusual from the pair. In fact, workers in the Cavendish often found Crick to be tactless, arrogant and noisy; one even went so far as to comment that he had “never seen Francis Crick in a modest mood.” Yet, a little over a century later, it is undeniable that Crick’s statement is true. Using information derived from a number of other scientists, primarily Rosalind Franklin and Maurice Wilkins of King’s College, the duo solved a puzzle that had plagued biologists for decades; they created a three-dimensional model of the DNA helix.
Gregor Mendel was born into a German family, as a young man Mendel worked as a gardener and studied beekeeping. In his later life Mendel gained his fame as the founder of the modern science of genetics. The research that was his claim to fame was his pea plant experiment. Mendel looked at seven different characteristics of the pea plants. For example with seed colors when he bred a yellow pea and green pea together their offspring plant was always yellow. Though, in the next generation of plants, the green peas reemerged at a 1:3 ratio. To explain what he had discovered, Mendel put together the terms “recessive” and “dominant” in reference to specific traits. Such as, in the previous example the green peas were recessive and the yellow peas
In Gregor Mendel’s first experiment, he used pea plants to observe plant hybridization. Mendel chose pea plants due to four main factors: he knew that he would be able to expect segregation of traits among the offspring of the plants, there
From simple heredity experiments with garden peas, to cloning sheep, the field of genetics has come a long way. Now we are closer to mapping out the human genetic map due to advances in technology, and years and years of research. Perhaps the most influential and groundbreaking scientist, Gregor Mendel, he was responsible to provide a path to where genetics is now today with his experiments of garden peas.
Deoxyribo Nucleic Acid (DNA) is a chromosome found in the nucleus of a cell, which is a double-stranded helix (similar to a twisted ladder). DNA is made up of four bases called adenine (A), thymine (T), guanine (G), and cytosine (C), that is always based in pairs of A with T and G with C. The four bases of A, C, G, and T were discovered by Phoebus Levene in 1929, which linked it to the string of nucleotide units through phosphate-sugar-base (groups). As mention in Ananya Mandal research paper, Levene thought the chain connection with the bases is repeated in a fix order that make up the DNA molecu...
The discovery of DNA is quite mind-blowing. Rumor has it that James Watson and Francis Crick discovered DNA, but they actually did not. It all started in 1869, with a well-known German biochemist named Friedrich Miescher who isolated, analyzed, and recognized a distinctive macromolecule known as DNA. Years later, on the morning of February 28, 1953, Watson and Crick came into the picture, as they announced that they “had discovered the secret of life” (Markel 2013). Their discovery of the double helix made them publish a paper in the 1953 issue of Nature, describing the structure of DNA, which resulted them to receive the Nobel Prize in 1962.
"The discovery of the structure by Crick and Watson, with all its biological implications, has been one of the major scientific events of this century." (Bragg, The Double Helix, p1) In the story of The Double Helix, James Watson tells of the road that led to the discovery of life's basic building block-DNA. This autobiography gives insight into science and the workings within a professional research laboratory that few members of society will ever be able to experience. It also gives the reader an idea of the reality of life for one scientist and how he struggled with the problem of DNA. However, the author's style is marked by his lack of objectivity and inclusion of many biased opinions and personal prejudices.
After Mendel’s death, his work was rediscovered by Carl Correns, Hugo de Vries, and Erich von Tschermak-Seysenegg. Although Mendel’s work was not recognized until the 1900s, he is still remembered and regarded as the father of modern genetics. Mendel’s genetic research with peas helped geneticists discover and develop new theories for Mendel’s unfinished work; therefore, the simple Mendelian genetics distinguished the environmental impact on phenotype, endured as the foundation of human genetics, and analyzed results for family histories. Mendel, along with his experiments and genetic laws, will always be credited as the man whose work prospered to new discipline within Biology and
The majority of scientific work in genetics and genomic sequencing has been done in the last 155 years. In 1859, Charles Darwin published On the Origin of Species where he proposed evolution by natural selection. Evolution is the change of inherited characteristics of biological populations over successive generations.Yet, the principals of genetics required to explain how characters are ...
In the late 1860’s, a Swiss chemist named Friedrich Miescher first identified DNA. It can be said that he successfully completed the first part of the gene puzzle. He found what he called nuclein in the pus he extracted from a surgical bandage. He called it “nuclein” because it was found in the nucleus of the cell. The term “nuclein” was later changed to “nucleic acid” and eventually to “Deoxyribonucleic Acid” or “DNA.” At this point, many scientists did not realize how important this information was, therefore many ignored this information. Then, in 1919, an American biochemist named Phoebus Levene laid the groundwork for the future studies of DNA. He was the first to identify and explain how the nucleic acid components, sugar and phosphate, combine to form nucleotides. Next, Erwin Chargaff, a student of Cambridge, fortified the foundation of studies that had already been made. He created a set of rules called “Chargaff’s rules.” The first rule he established is that, in human DNA, the number of adenine components equals the number of thymine components and the number of guanine components equals the number of cytosine components. The second rule he established was that the form of DNA is different in a human compared to in an animal. He found strong ...
Francis Crick: He does the same research with Watson and they are both teammates. He is also eager to know what is in DNA and the relationship of it with the double-helix, but at the same time is disorganised, and expected Watson to do a majority of work.
have played an important part in the scientific world by putting forth their discoveries for
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 insight’s 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 the most important and describe their significance to society, heath, and the culture of modern life.
After scoping out the DNA-research picture, Watson got a job at the Cambridge lab where Francis Crick, Max Perutz, and Sir Lawrence Bragg were working. Francis was rumored to be immodest and exceedingly talkative, ...