Question

1. Making Reference to the Central Limit Theorem, explain why we expect many continuous traits in natural populations to have distributions that are nearly normal.

2. Explain the main idea behind how GWA is carried out and what properties differentiate GWA mapping from classical linkage mapping.

Answer 1

Central limit theorem is most fundamental result among all stastics. It finally conclude that if the repeated sampling is significant or not (statistically). It also conclude the common behaviour among all samples. It also reveals the distribution of all means of sample from a solution when drawn. It is fact that when sample size increases, the distribution of means will approach normality, automatically, and this result will remain same even after any change in original population.

GWA ( Genome wide association) study:- In this study the genome wide set of genetic variants is studied to check whether the genome set belong to trait or not. In this entire genome is studied. It is based on fact that any two genome can be differ in many aspects such as SNPs, some variations like deletion, insertion, these alteration finally results in change in trait or phenotype.

Classical linkage mapping studies only a prespecified genwtic region while in GWA entire genome is studies. GWA is complex process when it comes to derive result from it statistically. Genetic linkage mapping is useful for single gene disorders, while GWA can also used for common complex diseases where gene mapping failed. In GWA studies biobanks are generated where genome are reposited which reduce the difficulty of collecting samples as well as reduced cost.