In this chapter, you have learnt the classical Mendelian techniques of gene mapping and modern techniques of gene, transfer to genetically engineer the host organism and use it as a medicine factory or agricultural crop factory or even as a disease factory to induce immunity against diseases in humans or animals
Mendel's laws of inheritance are summarized as follows:
Variations in an organism are important to it as they help the organism to adapt to changing environment, so that it can survive and reproduce successfully. Variations are also the raw material of evolution as new variants arise through mutations or recombination of genes during reproduction by sexual reproduction, which then survive because they have some advantage over their parent species (due to genetic variation).
Genotype refers to the genetic make-up of an organism. Phenotype is the physical or observable expression of that genotype, or how a particular gene influences the appearance or behavior of an organism.
One example is eye color—a child may have brown, blue or green eyes because of their parents' genetics and whether those genes were passed down to them through genes such as OCA2 (which determines brown eyes) or HERC2 (which determines blue/green eyes).
In humans, sex-linked disorders are more common in males than females. For example, hemophilia is one such disorder. This condition is caused by a deficiency of clotting factor VIII (FVIII), which is normally found on chromosome X and affects only males who have inherited a defective gene from their mothers. Females express FVIII normally because they have two copies of this chromosome and any mutation will be masked by their other copy.
In the translation process, messenger RNA (mRNA) is used. It is a single-stranded molecule that carries information from DNA to ribosomes. mRNA contains three main regions: 5’-, 3’-, and central segments. The 5' end of mRNA contains a start codon, which is coded by ACGTG in DNA and AUG in RNA; it signals the beginning of protein synthesis at this point. The 3' tail contains stop codons; these are also coded into DNA as TAA/TAG or UAA/UAG, depending on whether they're tryptophan or phenylalanine residues respectively.
In addition to carrying information from DNA to ribosomes during translation processing, another function of RNA includes regulating gene expression levels through transcription factors and messenger RNAs (mRNAs).
Induced mutations are those that occur in an organism when it is exposed to some chemical or physical agent. The most common example of this type of mutation is radiation. There are two types of induced mutations:
Induced point mutations: These are random changes in DNA sequence due to the addition, deletion or substitution of one base pair at a specific location in the genome. When this happens, it can cause a change in the amino acid sequence of proteins encoded by genes at that location; these may be non-functional (or have reduced function), have multiple functions and/or be toxic to the cell.
Induced structural alterations: These are changes involving large regions of DNA (such as deletions) resulting from exposure to mutagens like ultraviolet radiation or chemicals such as ethyl methanesulfonate (EMS).
Leguminous plants have been selected as model plants for genetic transformation studies for several reasons. These include:
Transgenic animals can be used for the production of human and animal vaccines, medicines and genes.
Genetic engineering is considered to be an advance tool in medical sciences due to its ability to treat various diseases by genetic modification techniques. Genetic engineering techniques are also used to create new vaccines and medicines through gene therapy which will help us fight against diseases like cancer, HIV/AIDS etc., In addition to this it has been used successfully in creating transgenic animals such as pigs, goats etc., These transgenic animals have been grown up so that they can produce milk containing proteins like human insulin or clotting factors needed by humans suffering from hemophilia A & B respectively which helps them live longer than normal life span
A gene is a unit of heredity that can be passed from one generation to another. It carries information for the production of proteins and other cellular components. Genes are located on a linear DNA molecule, in a very specific location which determines their function and behavior in the cell.
A gene is composed of two parts:
The book is an excellent guide for every biotechnology student, who wants to know about the basics of molecular biology and genetics. The book also provides a brief introduction to cell and molecular biology, which makes it easier for students with no previous knowledge in genetics or molecular biology.