Each species and genus of living creature has an exclusive collection of inherited qualities and characteristics so as to make it diverse and different from other organism. Every organism possess their own developmental arrangement or plan frequently described as a type of “blueprint” for the construction of a specie — which can be determined in the DNA molecules that can be found in cells (Silverstein & Nunn, 2002). The developmental arrangement influences the qualities and characteristics that can be inherited.
For the reason that organisms that belong with the same like species has the similar developmental design, organisms that belong to the same kind of species more often than not to be similar to another specie. Family reunions offer excellent opportunities to see nature’s heredity systems at work: gatherings of people who are tied to a common ancestry by their genes. Distinctive features and traits that run in families bear witness to the persistence of genes transmitted from generation to generation through the process of reproduction.
In plants, lineage can be traced by way of similarities in flower form, seed color, stature, hardiness in the face of cold or drought, unique biochemical products, and so forth. Each plant or animal characteristic is determined by a particular gene or set of genes. When mixed by sexual process, the new gene combinations result in offspring having recognizable family traits, together with unmistakable, individual qualities. This is no better illustrated than in the human species in which random assortments of several common features make each family member recognizably different from the others.
The underlying mechanism of gene mixing can be traced in plants more readily than in people, because cross-breeding can be controlled by selecting parents with specific traits; and several generations of plants can be produced within a comparatively short time, especially in annual species. It is not surprising therefore, that the fundamental laws of genetics were first recognized by a keenly observant monk and gardener in the repeated hereditary patterns of his plants.
The precise work of Gregor Mendel (1822-1884), an Austrian monk, on the hybridization of common peas n his monastery’s garden and his innovative interpretation of the experimental results have been recognized as one of the greatest intellectual accomplishments by a single individual in the history of science. Over eight years, Mendel examined approximately 30,000 pea plants, subsequent to a number of plants during as many as seven generations.
Mendel breeds plants that vary in particular qualities, and afterward tallied the quantity of offspring that displayed every structure of the qualities he was investigating (Elrod & Stansfield, 2002). Subsequently, he allow the hybrids and their progeny fertilize themselves. Mendel’s discoveries were the starting point for the science of genetics. Mendelian genetics revolutionized the biological sciences and provided theoretical support for Darwin’s concept of speciation through natural selection.
Genetics is a branch of biology that deals with heredity and variation. It is the study of how traits are passed on. The life blood of the science of genetics is the variation that occurs within and among plant and animal species. Heredity can be defined as the study of transmission of development potentialities, (genes) and their expression from generation to generation. It is the term used to describe the passing traits from parents to children. Every species has its own set of traits that it transmits to its off-spring.
In general, heredity explains the similarity between the parents and offspring. The similarity is due to transmission or inheritance of factors (genes) from the parents to offspring. Heritable characters are transmitted to the offspring through a very narrow bridge of gametes. In the act of fertilization the gametes from two parents come together. Thus the characters expressed by the offspring will be the sum total of the characters of both parents. Genes are basic building blocks that were inferred long before it was possible to examine their biochemical makeup.
In the twentieth century, it was determined that genes are segments of deoxyribonucleic acid (DNA), molecules that exist in the nuclei of cells and that are biochemically encoded with all of the information necessary to reproduce themselves, to cause cells to diversify into many different types that make up a living organism, and eventually to produce an adult organism with characteristics that are common to all normal members of the species, and unique to individual (Freedman, 2005). Genes determine all of the inherited traits. It contains coded information for the production of proteins.
DNA is normally a stable molecule with the capacity for self-replication (Lysenko, 2001). On rare occasions, a change may occur spontaneously in some part of DNA. This change is called a mutation; it alters the coded instructions and may result in a defective protein or in the cessation of protein synthesis. (Silverstein & Nunn, 2002). Genes may be dominant or recessive. The dominant gene, if present, will always appear in an offspring. If two dominant genes are inherited, the resulting trait will be a combination of the two inherited characteristics.
Within a chromosome, there are many genes, each controlling the inheritance of a particular trait (Willett, 2006). For example, in pea plants, there’s a gene on the chromosome that codes for seed coat. The position of a gene on a chromosome is called a locus. It usually consists of a pair of heredity factors which are called alleles. Each organism usually carries two alleles for a particular trait. That is, alleles make up a gene, which in turn produce a trait (Elrod & Stansfield, 2002). It should be realized that genetics is a natural outgrowth from the study of organic revolution.
The conception of evolution began as evolution began as a speculation, but became scientific in connection with the work of Lamarck and Darwin. In such work the method was that of observation and inference. It was in 1900 that a new method for the study of evolution was made by De Vries. The new method is experimentation. In developing this experimental method the facts of inheritance began to accumulate. In brief, therefore, genetics is the experimental study of inheritance. Applications of genetics in plants contribute to the greatest importance new researches and their evolution.
WORK CITED
Lysenko, T. (2001). Heredity and Its Variability. Honolulu, Hawaii: The Minerva Group Inc. Elrod, S. and Stansfield, W. (2002). Theory and Problems of Genetics. New York, NY: McGraw-Hill Professional Willett, E. (2006). Genetics Demystified: A Self-teaching Guide. New York, NY: McGraw-Hill Professional Freedman, J. (2005). How Do We Know about Genetics and Heredity. New York, NY: The Rosen Publishing Group Silverstein, A. and Nunn, S. (2002). DNA. Brookfield, Connecticut: Twenty-First Century Books