Heredity is the transmission of characteristics from one generation to the next. It is the most important process in the development of life and is the basis for the transmission of traits that are both beneficial and detrimental. This is one of the fundamental concepts of biology as it explains how living things are related to each other. This concept is based on the idea that organisms have a genetic make-up that they carry through their lifetime. There are three reasons for heredity. The first is that heredity is a function of the environment. The second reason is that heredity is the result of genes. And the third is that heredity is a function of the combination of the genes.
Reasons for heredity:The reasons for heredity are many, but they can be classified into four main categories: genes, epigenetics, environment and nutrition.
Genes:
Genes are pieces of information that create the blueprint of an organism. These can be passed on from generation to generation, and contribute to the traits and characteristics of an individual. Genes are the basic units of inheritance. There are two main categories of genes: Mendelian and non-Mendelian. Mendelian genes are passed directly from parents to the offspring; they are responsible for traits such as eye colour, height and weight. Non-Mendelian genes are passed indirectly along a chain of genetic material that is affected by the Mendelian genes.
Epigenetics:
Epigenetics refers to changes in gene expression caused by other factors in the environment rather than changes in the genetic code itself. It is the study of how factors like environment, diet, stress, smoking and even drugs can cause changes to a gene that affect how it is expressed. It is a relatively new field of biology. Epigenetics helps to explain how certain genes can be switched on or off in the body.
Environment:
Heredity is the product of the interaction of the child’s genes with the environment. It is controlled to a great extent by the genes carried by the parents. The environment is the sum total of the experiences and surroundings of the child. A child’s experience of the environment is often a combination of the experiences of the parents, family and peers.
Nutrition:
As a result of the high metabolic rate and increased energy demands required to develop and maintain a large body mass, nutrition may have an important role in regulating the expression of genetic information. In animals whose gestation and lactation periods are relatively short, nutrient-related epigenetic changes may be more important than nutrition-related genetic changes in affecting the expression of genetic information. The inheritance of obesity is a key example of the role of nutrition in the risk for many kinds of disease. For instance, an obese grandmother may increase the risk for obesity in her grandchildren.
Hereditary disorders:
Hereditary disorders are genetic disorders that occur when a germ cell or gamete carries a defective gene and passes it to the next generation. The disorders result from a single mutation in a gene, usually in the germ cells during gametogenesis or zygote formation. Some of the disorders are Mendelian (Mendel’s laws) while others are non-Mendelian (non-Mendel’s laws). Hereditary disorders are an abnormality of genetic inheritance, which can affect the physical, mental and social well-being of the person. The most common disorders are the following: haemophilia, thalassemia, sickle cell disease, cystic fibrosis, Duchenne muscular dystrophy and Huntington’s disease.
Cause of hereditary disorders:
The human body has a number of hereditary disorders that are passed on from parent to child. A hereditary disorder is caused by the heredity of genetic material from the parent. A major cause of hereditary disorders is a mutation in a gene. A mutation can affect the normal structure or function of a gene. They also occur when a germ cell or gamete carries a defective gene and passes it to the next generation.
Some hereditary medical conditions:
A hereditary medical condition is a physical or mental condition that is passed on from generation to generation within a family. It can be inherited or acquired. Some hereditary conditions are the result of genes passed from parents to children. Some medical conditions such as cystic fibrosis, Huntington’s disease and Duchenne muscular dystrophy are hereditary and have been the focus of clinical research. These conditions also range from diabetes and heart disease to cancer and mental illnesses. Another example is familial Mediterranean fever (FMF). FMF is a rare genetic inflammatory disease that can cause pain, fever, and joint inflammation. FMF can be fatal if not treated. A child inheriting cystic fibrosis can pass this disease on to their children. A child inheriting sickle cell anaemia can pass this disease on to their children.
Conclusion:
Heredity is the passing on of traits from a parent to a child. They can be passed down through a parent’s genes or from a parent to the child through the environment. Heredity plays a big role in evolution. It is the main force that drives species to change and adapt to their environment. Heredity is the most important part of human nature because it is the cause of all diversity in human individuals and societies. Heredity determines not only how individuals are in the world, but also how they think and behave and how they live and die.