Genotype
Definition
The genotype of an organism refers to its complete set of genetic instructions, which is made up of DNA. This DNA contains genes that determine various traits and characteristics of the organism. Each gene can have different forms called alleles, and the combination of these alleles determines the genotype. For example, a plant might have two alleles for flower color—one for purple and one for white.
Example Scenario
Imagine you're studying petunia flowers, which come in purple or white. The color is determined by two genes: one for purple (P) and one for white (p). Each plant receives two copies of this gene, one from each parent. So, a plant's genotype could be PP (purple), Pp (purple), or pp (white). If you cross a PP plant with a pp plant, all offspring will have the genotype Pp but will show purple flowers because the P allele is dominant over p.
Why It Matters
Understanding genotypes is crucial in various fields. In medicine, it helps predict and manage hereditary diseases. For instance, knowing if someone has a genotype prone to certain conditions can allow early intervention. In agriculture, it aids in breeding crops with desired traits, like drought resistance. Additionally, studying genotypes in evolutionary biology reveals how species adapt over time. It also plays a key role in personalized medicine, where treatments are tailored based on individual genetic profiles, ensuring more effective and fewer adverse reactions to medications.