Genetic genetic essay has been in practice for many years in the domestication of plants and animals, but despite its unprecedented progress, gene editing in humans, especially in embryonic stem cells, is one of the major controversies in health and science field nowadays. This method of ordering genes on a chromosome is called a linkage map. Therefore, the percentage of recombinant gametes reflected in the percentage of recombinant offspring correlates with the distance between two genes on a chromosome. A good example is athletics. The branch of biology that deals with heredity, especially the mechanisms of hereditary transmission and the variation of inherited characteristics among similar or related organisms is known as genetics, genetic essay. Essays on Genetic essay Engineering.
Genetics In Mendelian Genetics
What are genetics? It is the study and the variation of inherited characteristics that make up new life. Every child inherits genes from both of their biological parents. Some of these traits may be physical; hair, eye color or skin colors, etc. Genetic essay the downfall some genes might carry certain diseases or disorders. Each gene is a piece of genetic information and all DNA in the cell make up the human genome. The wonderful thing about genetics is the technology that has been made for it and how advanced it is to now do what ever it takes to fix the unborn. Genes generally express their functional effect through the production of proteins, which are complex molecules responsible for majority of functions in the cells in the body, genetic essay.
Heredity is a biological process where a parent passes certain genes onto their children or offspring's which all falls under the genetic essay of genetics. Genetic information with genes from their parent lies within the cells nucleus of each living cell in the body. The genes will be rested inside the chromosomes in the human body. In the body, we have up to 46 chromosomes divided equally between the mother and father. A chromosome is an organized structure of DNA and genetic essay that is found in cells that plays a major role in genetics.
There are about 20, genes located on one of the 23 chromosome pairs found in the nucleus. Chromosomes are the structures that hold our genes. Genes are the building blocks of heredity; every child inherits genes from both of their biological parent. Some traits are physical for example; eye, hair and skin color will be brought down from the parent to the offspring. The down side of inheriting different genes is that the offspring may inherit some disorders or disease. A single gene disorder is where a mutation affects one genetic essay, for example sickle cell anemia. Another disorder that can occur from genes is a chromosomal disorder is where the chromosomes or part of it is missing o Continue reading this essay Continue reading. Toggle navigation MegaEssays. Saved Essays.
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This ORF is positioned in the antisense side left of the ORF1 and ORF2 already known and called ORF0. Biodiversity Gene Genetic Engineering. Introduction In the early years of scientific investigations in the field of heredity, the methods used to obtain data were considered genetical but once the physical basis of genetic conditions were recognized several studies were performed using methods of both cytology and genetics, using the Cell Gene Genetic Engineering. In were million cases of malaria in 91 countries and people were killed Experiment Gene Genetic Engineering. Introduction Advances in atomic science methods have given the premise to revealing for all intents and purposes boundless quantities of DNA markers.
The utility of DNA-based markers is for the most part dictated by the innovation that is utilized to uncover DNA-based polymorphism. Right now, Multi-objective evolutionary algorithm is a popular approach that has been widely used in optimization problems. This research on using Multi-objective genetic algorithm for motif discovery MOGAMOD was the first study to apply multi-objective genetic algorithm in the motif finding problem. By maximizing three conflicting objectives RNAi is a way of silencing the BLG gene using specifically designed molecules of RNA that target the mRNA from the BLG gene and Gene Genetic Engineering Protein. CRISPR is a breakthrough in genetic editing technology, introduced in Secondary metabolites SM are low molecular weight organic compounds which produce from some of the primary metabolic biosynthetic pathways and interconnected with primary metabolite to gain the necessary amount of energy, carbon, and nitrogen.
Secondary metabolites are not essential for growth and produced after growth My understanding of epigenetics is directly linked to my understanding of how basic genetics itself works. Gene Genetic Engineering Human. The USDA should restrict the commercial production of the genetically engineered eucalyptus tree. Firstly, the technology involved is not mature enough at this stage, thus, if the production happens on a large scale, serious consequences may happen. Genetics are the result of adapting to the Genetic Engineering Plant Trees. Kibera is the largest informal settlement in Nairobi, Kenya and one of the largest in Africa and the world.
It is is located 7km southwest of Nairobi and houses approximately one million people and several animal species. Conditions in Kibera are extremely poor and heavily Use of genome editing and altering to design and engineer the attributes of future children has been supported and endorsed by the Nuffield Council on Bioethics; the report stated that it is morally and ethically permissible to use genome alterations for altering the genes of Genetic Engineering Genetic Modification. Feeling stressed about your essay? Starting from 3 hours delivery. Agriculture Essays Evolution Essays DNA Essays Hermit Crab Essays Aliens Essays Black Hole Essays Mars Essays Force Essays Apoptosis Essays Rat Essays.
If pea selfing continues over many generations the pea plants will be homozygous or have an identical pair of genes for a certain characteristic. These plants will contain either two identical recessive genes homozygous recessive for a characteristic or two identical dominant genes homozygous dominant for the same characteristic and are considered pure-breeding for those characteristics. For example, purple flower colour in peas is dominant and white flower colour in peas is recessive. When a white flowered homozygous recessive pea plant is crossed with a purple flowered homozygous dominant pea plant, the resulting offspring all has purple flower colour. The gene composition genotype for the flower genes in each of these types of pea plants is represented as shown below:.
Under this theory, one tall parent and one short parent would produce a child of medium height. Most ordinary observations seemed to support this hypothesis, which rejected the notion of discrete units of inheritance i. However, this theory was poorly equipped to deal with such phenomena as two brown-eyed parents giving birth to a blue-eyed baby. Like that, when Mendel cross- pollinated one variety of pure bred plant with another, these crosses would yield offspring that looked like either one of the parent plants, not a blend of the two. In another instance, when Mendel cross-fertilized plants with wrinkled seeds to those with smooth seeds, he did not get progeny with semi-wrinkled seeds.
Instead, the progeny from this cross had only smooth seeds. In general, if the progeny of crosses between pure bred plants looked like only one of the parents with regard to a specific trait, Mendel called the expressed parental trait the dominant trait. His historic experiments led him to the conclusion that inherited characteristics were carried in discrete, independent units later named genes. Mendel first crossbred one tall, true-breeding plant with one short, true-breeding plant. Contrary to the blending theory, all the offspring were tall. In terms of genotype, the original tall plant was TT two dominant alleles; homozygous , the short plant was tt two recessive alleles; homozygous , and the second-generation plants were Tt one dominant and one recessive allele; heterozygous.
When Mendel next allowed these plants to self-fertilize, he found that the short trait reappeared in the third generation. The ratio of short to tall plants was almost exactly Their genotypes were as follows -1 short tt : 2 tall Tt : 1 tall TT. Based on these observations Fig. Essay on the Punnett Square : Mendel worked by observing characteristics phenotypes and calculating the ratios of each type to form his principles of inheritance. One of the most common methods of determining the possible outcome of a cross between two parents is called a Punnett square. To perform a Punnett square one must first figure out all the possible combinations of the alleles to be studied for each parent.
The possible gametes for one parent go on the X axis and the possible gametes for the other parent go on the Y axis one allele in each cell of the upper row traditionally the mother and rightmost column traditionally the father. The gamete combinations are then paired in the squares below and to the side of each type, i. Eye colour in human is much more complex. A mother and father, both having the brown eye phenotype, have a child. We know that both parents carry the gene for blue eye colour and therefore are heterozygous for this trait. These parents can either donate a dominant B to the gamete or a recessive b to the gamete Fig.
There are several known X-linked characteristics in humans but few, if any, Y-linked characteristics are usually reported. Females have two X chromosomes with one or the other X chromosome remaining active in a mosaic pattern in a tissue. Males have only one X chromosome so if the X chromosome of a male has a defective allele there is no companion X chromosome to compensate for the deficiency. A female must have the same defective allele on both her X chromosomes to demonstrate any deficiencies Fig. Mendel accomplished this work by calculating the ratios of observable characteristics of the offspring from known parental types. The first parental types were homozygous recessive and homozygous dominant pure breeding types. The parental generation or P generation, by definition, is always homozygous recessive and homozygous dominant for the traits to be studied.
The offspring which results from the mating of parental types P generation will always be heterozygous for the characteristic. In other words it says that, if two plants that differ in just one trait are crossed, then the resulting hybrids will be uniform in the chosen trait. When two pure breeding organisms of contrasting characters are crossed, only one character of the pair appears in the F1 generation, known as the dominant character example- tallness and the other unexpressed or hidden character is known as the recessive character example- dwarfness. When Mendel crossed a true breeding red flowered plant with a true breeding white flowered one, the progeny was found to be red coloured. The white colour suppressed and the red colour dominated. For each of the seven pairs of characters examined, it was observed that one allelomorph dominated over the other, so that F1 exhibits one or the other alternative phenotypes represented in the parents.
The simplest example of this phenomenon is called codominance, or incomplete dominance. When a white and a red flower are cross-fertilized, the second generation is all pink. However, when a pink flower is allowed to self-fertilize, the white and red attributes return. The colour ratios for this third-generation cross are — 1 white: 2 pink: 1 red. If red colour is designated R and white colour r, then pink colour not red or white is the phenotypic effect of genotype Rr. This is one type of pattern formerly used in support of the blending theory of inheritance.
Thus in certain cases the hybrid offsprings resemble one parent much more closely than the other but does not resemble it exactly, so the dominance is incomplete. This is termed as incomplete dominance Fig. Another example of codominance is the ABO blood typing system used to determine the type of human blood. It is common knowledge that a blood transfusion can only take place between two people who have compatible types of blood. Human blood is separated into different classifications on the basis of presence and absence of specific antigens or proteins in the red blood cells. The first allele is, i, the recessive of the three, and IA and IB are both co-dominant when paired together. If the recessive allele i is paired with IB or IA, its expression is hidden and is not shown. When the IB and IA are together in a pair, both proteins A and B are present and expressed.
The ABO system is called a multiple allele system for there are more than two possible allele pairs for the locus. There are four possible blood types in order from most common to most rare- O, A, B and AB. The O blood type represents an individual who is homozygous recessive ii and does not have an allele for A or B Table 6. Blood types A and B are co-dominant alleles. Co-dominant alleles are expressed even if only one is present. The recessive allele i for blood type O is only expressed when two recessive alleles are present. Blood type O is not apparent if the individual has an allele for A or B. Individuals who have blood type A have a genotype of IAIA or IAi and those with blood type B, IBIB or IBi, but an individual who is IAIB has blood type AB.
The law of segregations is a law of inheritance proposed by Mendel in Each character is controlled by a pair of factors genes. This law is also called law of purity of gametes. At formation of gametes, the two chromosomes of each pair separate segregate into two different cell which form the gametes. This is a universal law and always during gamete formation in all sexually reproducing organisms, the two factors of a pair pass into different gametes. Each gamete receives one member of a pair of factors and the gametes are pure. That is two members alleles of a single pair of genes are never found in the same mature sperm or ovum gamete but always separate out segregate. The factors of inheritance genes normally are paired, but are separated or segregated in the formation of gametes eggs and sperm , i.
Depending on a dominant-recessive crossing or an intermediate crossing are the resulting ratios or This concept of independent traits explains how a trait can persist from generation to generation without blending with other traits. It explains, too, how the trait can seemingly disappear and then reappear in a later generation. The principle of segregation was consequently of the utmost importance for understanding both genetics and evolution. The crossing of two plants differing in one character is called monohybrid cross. Mendel carried out monohybrid experiments on pea plants and based on the results of monohybrid experiment, he formulated the law of segregation.
Mendel selected two pea plants, one with a tall stem and the other with a dwarf or short stem. These plants were considered as parental plants P and were pure breed. A pure plant is one that breeds true in respect of a particular character for a number of generations. The pure-bred tall and dwarf plants were treated as parents and were crossed. Seeds were collected from these plants. These seeds were sown and a group of plants were raised. These plants constituted the first filial generation F1 generation. All the F1 plants were tall and were inbred. The seeds were collected and the next generation F2 was raised. In the F2 generation, two types of plants were found. They were tall and dwarf.
Mendel counted the number of tall and dwarf plants. Thus the tall plants occurred in the ratio 3: 1 Fig. The Principle of Independent Assortment describes how different genes independently separate from one another when reproductive cells develop. Mendel formulated the Principle of Independent Assortment from the observations he got from the dihybrid crosses, which are crosses between organisms that differ with regard to two traits. It is now known that this independent assortment of genes occurs during meiosis in eukaryotes. Meiosis is a type of cell division that reduces the number of chromosomes in a parent cell by half to produce four reproductive cells called gametes.
In humans, diploid cells contain 46 chromosomes, with 23 chromosomes inherited from the mother, while a second similar set of 23 chromosomes inherited from the father. Pairs of similar chromosomes are called homologous chromosomes. During meiosis, the pairs of homologous chromosome are divided in half to form haploid cells, and this separation, or assortment of homologous chromosomes is random. This means that all the maternal chromosomes will not be separated into one cell, while all the paternal chromosomes are separated into another. Another feature of independent assortment is recombination.
Recombination occurs during meiosis and is a process that breaks and recombines the pieces of DNA to produce new combinations of genes. Recombination scrambles pieces of maternal and paternal genes, which ensures that genes assort independently from one another. It is important to note that there is an exception to the law of independent assortment for genes that are located very close to one another on the same chromosome because of genetic linkage. A dihybrid cross is a breeding experiment between P generation parental generation organisms that differ in two traits. Mendel determined what happens when two plants that are each hybrid for two traits are crossed.
Mendel therefore decided to examine the inheritance of two characteristics at once. Based on the concept of segregation, he predicted that traits must sort into gametes separately. By extrapolating from his earlier data, Mendel also predicted that the inheritance of one characteristic did not affect the inheritance of a different characteristic. Mendel tested the idea of trait independence with more complex crosses. First, he generated plants that were pure bred for two characteristics, such as seed colour yellow and green and seed shape round and wrinkled. These plants would serve as the Pi generation for the experiment. In this case, Mendel crossed the plants with Round and Yellow seeds RRYY with plants with wrinkled and green seeds rryy.
From his earlier monohybrid crosses, Mendel knew which traits were dominant- round and yellow. So, in the F 1 generation, he expected all round, yellow seeds from crossing these pure bred varieties, and that is exactly what he observed. Mendel knew that each of the Fi progeny were dihybrids; in other words, they contained both alleles for each characteristic RrYy. He then crossed individual Fi plants with genotypes RrYy with one another. This is called a dihybrid cross. The outcome shows a phenotypic ratio of 9 of the offspring having yellow round peas, 3 having yellow wrinkled peas, 3 having green round peas and 1 having green wrinkled peas.
This is a classic phenotypic ratio which is always the result in a dihybrid cross between two heterozygotes with unlinked traits. The proportion of each trait was still approximately for both seed shape and seed colour. In other words, the resulting seed shape and seed colour looked as if they had come from two parallel monohybrid crosses; even though two characteristics were involved in one cross, these traits behaved as though they had segregated independently. From these data, Mendel developed the third principle of inheritance- the principle of independent assortment i. If people understood that their success is a result of superior genes and not their commitment, they would feel compelled to split their genetic fruits with others in society. On the other hand, they would be reluctant to split their success with the less fortunate in society if they learned that success was not a result of good luck.
The people that are genetically enhanced would look down upon the ones that are not and take advantage to exploit them. Consequently, at times the enhanced humans may fail to achieve their objectives. They may consider themselves to be mutants who were developed in test tubes thus feeling to be unworthy. Based on films such as Gattaca, it is evident that genetically enhanced persons are highly susceptible to suffering from depression Seck To ensure that people shun using genetic enhancements there are numerous procedures that ought to be adopted. In the issue of athletics, all countries need to promote and support those people that are found to be naturally talented in athletics. People need to be educated on some of the negative effects of genetic enhancements as well as encouraged to tolerate the differences in capabilities exhibited in society Seck Another approach that ought to be used in eliminating cases of unfairness that arise from genetic enhancement is banning the practice Devettere All countries need to declare the practice illegal and endorse heavy punishments on those found to practice it.
This would discourage people from practicing genetic engineering. It would also ensure that even the rich do not take advantage of their wealth to acquire the technology and use it in exploiting the poor. It would not be good to limit people from pursuing goals they wish to pursue. Based on equality, the poor would claim to have significantly achieved their objectives Seck pp. However, the rich would be disadvantaged as they would be prevented from pursuing their goals. This underlines the need for health professionals to adhere to professional ethics when using genetic enhancements. Health professionals ought to only practice genetic enhancements only on very crucial events.
For instance, they need to only practice it if it will benefit the fetus or the infant Devettere pp. This would help in ensuring that the rich do not take advantage of its accessibility to exploit the poor. Finally, there is a need for health professionals to ensure that everybody has access to the technology regardless of his or her income. By so doing, everybody will make use of the technology thus ensuring that there is equality and fairness in society. Borenstein, Jason. Devettere, Raymond J. Practical decision making in health care ethics: Cases and concepts. Washington, DC: Georgetown University Press, Glover, Jonathan.
Choosing children: The ethical dilemmas of genetic intervention. New York: Oxford University Press, Mehlman, Maxwell J. Human subjects protection in biomedical enhancement research. The Journal of Law, Medicine, and Ethics 36 : Seck, Chris. Arguing for and against genetic engineering.
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