Question 1: Describe DNA sequence variations that are often observed among individuals of the same species. Discuss the possible phenotypic consequences of these DNA sequence variation, give examples, if possible. Discuss the technologies or methods that are often used in detecting each of these variations.
Question 2: Describe the field of epigenetics study. How doepigenetic modifications affect gene expression and phenotype?
Question 3: Briefly describe the principles and applications of 2-dimensional gel electrophoresis, including 2d DIGE, for analysis of proteins.
Question 4: How does real time PCR work to quantify the initial amount of the DNA template? How should the method be modified to quantify the initial amount of RNA template extracted from tissue or cells?
To discuss the DNA sequence variation, the primary concept is genetic variation, which is the variation in set of alleles of any gene. The prime source of this genetic variation is mutation. Once the parent genetic information is mixed to produce offspring this give rise to a new set of combination in the genetic makeup and also in this segregation process there are chances to get the mutated traits from the parents to offspring. Generally the mutations are rare and often neutral but the chances of a mutation to pass through the offspring depend upon natural selection and genetic drift.
The easiest approach to identify genetic variation among individual of same species is the observation of phenotype. According to Mendel the genetic variation can be qualitative judged eg. the color of flower petal. Also the measurement of genetic variation can be accessed quantitatively say height of individual. The variation in phenotype as a consequence of DNA sequence variation results from the order of nucleotides in a DNA. Since in the translational process DNA codes for protein expression with the help of various cofactors, enzymes etc. the order of amino acids that will be coded by DNA sequence can vary because of variation in DNA sequence. Such difference in the protein sequence can result in variation of protein structure and function