Have you ever wondered why people resemble their parents? The answer to this and other questions about inheritance lies in a specialized branch of biology called genetics. Geneticist found that most aspects of life have a hereditary basis and that many traits can appear in more than one form. For instance, human beings have blond, or red, or brown, or black hair. They may have one of several different types of blood, one or several colors of skin. Their ear lobes may be attached or free. They may or may not be able to manufacture certain enzymes. Some of these traits are much more important to the life of the individual than others, but all of them are hereditary. The geneticist is interested not only in the traits of man but in those of all other organisms as well. The study of inheritance depends on the differences as well as the similarities between parents and offspring over several generations. Heredity is very complex, and a geneticist cannot possibly analyze all the traits of an organism at once. Instead, he studies only a few traits at a time. Many other traits are present. As the geneticists work out the solution to each hereditary mystery, the geneticist must not forget that all organisms live in a complex environment. The environment may affect the degree to which a hereditary trait develops. The geneticist must try to find out which of the many parts of the environment may affect his results. The factors must be kept as constant as possible by using controlled experiments. Only then can he tell that the differences observed are due to heredity. Heredity determines what an organism may become, not what it will become. What an organism becomes depends on both its heredity and environment. The modern science of genetics started with the work of Gregor Mendel. He found that a certain factor in a plant cell determined the traits the plant would have. Thirty years after his discovery this determines was given the name gene. Of the traits Mendel studied, he called dominant those at showed up in the offspring and recessive those The question I will ask is: how much of the variability observed between different individuals is due to hereditary differences between them, and how much to differences in the environments under which the individuals developed? In most organisms, including man, genetics information is transmitted from mother to daughter cells and from one generation to the next by deoxyribonucleic acid (DNA). Knowledge of the heredity or inheritance of plants and animals is important in many phases of our life. The question I will ask is: How much of the variability observed between different individuals is due to hereditary differences between them, and how much to differences in the environments under which the individuals developed? The purpose of designing a unit on �Heredity And Environment� is to help students learn more about themselves. They will learn why they develop into the kind of individual they are. The unit will discuss heredity traits and environmental conditions, chromosomes, DNA, studies of identical twins, and several diseases linked to heredity and environment. The students will do some hands on activities by constructing a model which represents DNA. They will explore plants with the exact same heredity and plants with different heredity. They will change the conditions in the environment to see the way the plant organisms with the same heredity may develop differently in different environments and why organisms with different heredity develop in the matter in which they do. Heredity is not the only thing that effects development. The environment also has an important effect. The unit can be taught to students in grades five through eight. The science and math teachers are encouraged to use a team teaching approach. Other features that will be included in the unit are content, lesson plans, resources, reading list and a bibliography. Genes and DNA
DNA, short for deoxyribonucleic acid,...
Please join StudyMode to read the full document