Quiz 24: Medical Genetics


Gene pool: Every gene contains alleles, every individual contains genes, the individuals are the members of a particular population, in a population individual can inter bread to produce its next generation; all the alleles present in a particular population are collectively called a gene pool of that particular population. The gene pool of a population can be described quantitatively by calculating the allele frequency in the population, the formula for allele frequency can be written as img Based on the allele frequency in a population we can determine the gene pool of that population. There is another method to describe gene pool by using Hardy-Weinberg equation; if 'p' and 'q' are two different alleles in population then the Hardy-Weinberg equation says that img In these two ways we can determine the gene pool in quantitative way.

Gene polymorphism is the existence of gene in two or more allelic forms. The genetic material is the part of DNA (Deoxyribonucleic acid) in eukaryotes and part of RNA (Ribonucleic acid) in prokaryotes. RNA is single stranded and DNA is double stranded. We cannot observe frequent polymorphisms in RNA. Poly peptide bonds can be observed in DNA and proteins. To detect the gene polymorphisms DNA level is quite useful than RNA and polypeptide level, because RNA and polypeptides cannot give complete information of gene polymorphisms. By analyzing DNA by using DNA finger printing or other techniques we can detect genetic polymorphism in a population.

In natural populations mating useful to maintain the population in the environment, to improve the population reproduction is the very useful and necessary process. Due to reproduction recombinations can occur, and new verity of population with advanced characteristics can be obtained. Along with these advantages mating have some disadvantages like inbreeding. Due to inbreeding the fitness of the offspring's will decrease, genetically disordered species may generate due to mating, sometimes diseases can spread from one organism to another organism because of mating. In human beings also mating is useful for the maintenance and improvement of the population. Random mating is useful for the generation of fit and resistant verities. Genetically better generation can be produced due to mating. Due to mutations and inbreeding the offsprings with less fitness will be produced, sometimes diseases like HIV (Human Immunodeficiency Virus) can spread from one organism to another organism because of mating. In agriculture mating will not be observed and reproduction is by pollen grains and ovum. The pollen grain of male plant or flower moves to stigma of female flower and reaches ovary, units with ovum and produces seeds, so in this way plants tries to maintain their population. The disadvantages are very small compared to advantages, some diseases may spread among the field due to reproduction is the disadvantagE.