Final answer:
The term 'genetic variation' describes the differences in specific genes among individuals, most notably through varying alleles and mechanisms like SNPs and structural changes. This variation accounts for the diverse traits and responses to environmental factors, including medications.
Step-by-step explanation:
Genetic Variation
The term genetic variation refers to differences in specific genes. Genetic variation is the basis for the diverse traits observed among individuals within a species. This variation starts with alleles, which are different versions of a gene. Alleles are responsible for the vast genetic diversity seen in humans. For example, the human blood type is determined by three possible gene sequences on a chromosome that codes for blood type: sequence A, sequence B, and sequence O. This results in different combinations such as AA, BB, AB, or OO, which correspond to different blood types.
Genetic variation can arise through different mechanisms, such as single nucleotide polymorphisms (SNPs) and structural variations like copy number variation (CNV), deletion, insertion, duplication, inversion, and translocation. SNPs involve changes in single nucleotide bases (A, C, G, and T), whereas structural variations can affect larger sections of DNA, changing the structure of chromosomes significantly.
The genetic makeup received from both parents leads to the unique combination of genes within an individual. Thus, the specific genetic composition can influence how individuals respond to drugs, the traits they exhibit, and their overall health. Recognizing the importance of genetic variation can help in understanding diseases and developing personalized medicine.