Gene is the basic physical and functional unit of heredity. Genes are made up of DNA. Some genes act as instructions to make molecules called proteins. However, many genes do not code for proteins. In humans, genes vary in size from a few hundred DNA bases to more than 2 million bases. An international research effort called the Human Genome Project, which worked to determine the sequence of the human genome and identify the genes that it contains, estimated that humans have between 20,000 and 25,000 genes.
Every person has two copies of each gene, one inherited from each parent. Most genes are the same in all people, but a few number of genes (less than 1 percent of the total) are slightly different between people. Alleles are forms of the same gene with small differences in their sequence of DNA bases. These small differences contribute to each person’s unique physical features.
Scientists keep track of genes by giving them unique names. Because gene names can be long, genes are also assigned symbols, which are short combinations of letters (and sometimes numbers) that represent an abbreviated version of the gene name. For example, a gene on chromosome 7 that has been associated with cystic fibrosis is called the cystic fibrosis transmembrane conductance regulator; its symbol is CFTR.
A gene pool is the total genetic diversity found within a population or a species. A large gene pool has extensive genetic diversity and is better able to withstand the challenges posed by environmental stresses. Inbreeding contributes to the creation of a small gene pool and makes populations or species more likely to go extinct when faced with some type of stress.
Gene pool refers to thorough genetic diversity that exists within a population. The larger the genetic pool, the more the diversity and the more opportunity this population will have to survive environmental stress that may impact on them. So gene pool is really good in the sense that the larger the gene pool, the more the survival of that particular population in terms of withstanding different things that may come in terms of environment.
A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can survive bouts of intense selection. Meanwhile, low genetic diversity (see inbreeding and population bottlenecks) can cause reduced biological fitness and an increased chance of extinction, although as explained by genetic drift new genetic variants, that may cause an increase in the fitness of organisms, are more likely to fix in the population if it is rather small.
When all individuals in a population are identical with regard to a particular phenotypic trait, the population is said to be 'monomorphic'. When the individuals show several variants of a particular trait, they are said to be polymorphic.
Gene pool centers refers to areas on the earth where important crop plants and domestic animals originated. They have an extraordinary range of the wild counterparts of cultivated plant species and useful tropical plants. Gene pool centers also contain different subtropical and temperate region species.
You must be logged in to post a comment.