Question

What is the genetic equilibrium? Write any four factors affecting the Hardy Weinberg equilibrium.

Answer 1

Hint: This is the equilibrium that remains constant from generation to generation where there is no mutation and all the members of the population have an equal rate of reproduction.

Complete answer:
The genetic equilibrium explains the condition of an allele or genotype in a gene pool such as a population where from generation to generation the frequency does not change. This is also known as Hardy-Weinberg equilibrium. Any factor that will disturb the alleles in a population is likely to affect the Hardy-Weinberg equilibrium.
-The factors that affect the genetic equilibrium and induce the variability in the population are as follows: mutations, recombinations during sexual reproduction, genetic drift, gene migration or gene flow, and natural selection.
-Factors affecting the Hardy-Weinberg equilibrium are:
1)Mutations:
- These are sudden, large, and inheritable changes in the genetic material can occur in all directions.
-Sometimes the mutations are preadaptive and appear even without exposure to a specific environment. These can express and become advantageous only when if it gets exposure to a new environment, the hatch only selects the preadaptive mutations that occurred earlier.
2)Recombinations during Sexual Reproduction:
Recombination during sexual reproduction involves the reshuffling of genes of chromosomes. Chances of recombination are more in those organisms which undergo sexual reproduction which involves gametogenesis followed by fertilization.
-Recombination also occurs during an independent assortment of chromosomes that is during the arrangement of bivalents during metaphase I of meiosis.
3)Genetic Drift:
-It always influences frequencies of alleles and is inversely proportional to the size of the population. So genetic drift is most important in very small populations in which there are increased chances of inbreeding which increases the frequency of individuals homozygous for recessive alleles, many of which may be deleterious.
-Genetic drift occurs when a small group separates from a larger population and may not have all the alleles or may differ from the parental population in the frequencies of certain genes.
- In a small population, a chance event, for example, a snowstorm may increase the frequency of a character having little adaptive value.
4)Gene migration:
In population genetics, the gene flow is also known as gene migration or allele flow. This is the transfer of genetic variation from one population to another. The two populations are considered to have equivalent allele frequencies and can effectively be a single population if the rate of gene flow is high.

Note: -It has been observed that only one out of 1,000 mutations is useful.
-genetic drift is a binomial sampling error of the gene pool, i.e. that alleles that form the gene pool of the next generation are a sample of the alleles of the present population.
-recombination occurs during crossing over when the exchange of genetic material occurs between the non-sister chromatids of homologous chromosomes during the zygotene stage of Prophase 1 of meiosis to form bivalents.