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INTRODUCTION: DNA replication, the basis for biological inheritance, is a fundamental process occurring in all living organisms to copy their DNA. This process is “replication” in that each strand of the original double-stranded DNA molecule serves as template for the reproduction of the complementary strand. Hence, following DNA replication, two identical DNA molecules have been [...]

The proto-oncogene can become an oncogene by a relatively small modification of its original function. There are three basic activation types: *A mutation within a proto-oncogene can cause a change in the protein structure, causing – an increase in protein (enzyme) activity – a loss of regulation * An increase in protein concentration, caused by [...]

A proto-oncogene is a normal gene that can become an oncogene due to mutations or increased expression. Proto-oncogenes code for proteins that help to regulate cell growth and differentiation. Proto-oncogenes are often involved in signal transduction and execution of mitogenic signals, usually through their protein products. Upon activation, a proto-oncogene (or its product) becomes a [...]

A gene that causes normal cell to become cancerous either because the gene is mutated or because the gene is expressed at the wrong time in development. An oncogene is a gene that, when mutated or expressed at high levels, helps turn a normal cell into a tumor cell. Many abnormal cells normally undergo a [...]

Split gene is a gene whose continuity is interrupted. An interrupted gene (also called a split gene) is simply a strand of DNA that contains both introns and exons. Most higher-level eukaryotes have interrupted genes and have longer introns than exons, creating a gene that is longer than its coding region. Interrupted genes are also [...]

Gene is a unit of genetic material composed of a sequence of nucleotides that provides a specific function to an organism. It regulates all the activities and attributes of an organism. They are found in the chromosomes in their specific loci and their main component is DNA. The modern names of gene are: 1. Recon: [...]

The effects of mutation are as follows: 1. Lethal: A good number of mutations can be lethal. 2. Sub-vital: Some may reduce the chance of survival of the incumbent. 3. Super-vital: Increase the biological fitness under a given set of environmental conditions. 4. Unchangeable: State of the organism remains unchanged.

The principal characteristics are: 1. Reservoir of Genetic Information. 2. Inherited along with coded information through generations. 3. Metabolic activities of the organisms are performed by translating its code. 4. Highly stable.

Mutation is a change in the nucleotide sequence of genetic materials whether by substitution, duplication, insertion, deletion, or inversion. Mutations provide genetic variations which are the raw materials of evolution. Mutations are of two type: 1. Spontaneous mutation: Usual mutation under natural conditions. 2. Induced mutation: Artificially induced mutation by mutagens.

Chemical oxygen demand (COD) is a measure of the ability of chemical reactions to oxidise matter in aqueous system. The results are expressed in terms of oxygen so that they can be compared directly to the results of biochemical oxygen demand (BOD) testing. The test is performed by adding the oxidising solution to a sample, [...]