Final answer:
Geneticists study Mendelian inheritance from phenotypic and genotypic perspectives to understand traits and diseases' inheritance patterns. Advances in genetics allow for better predictions of heritable traits, though complex diseases often involve environmental factors and multiple genes.
Step-by-step explanation:
Geneticists aim to understand Mendelian inheritance from two main perspectives:
1)
Phenotypic perspective
2)
Genotypic perspective
Under the phenotypic perspective, the focus is on observable characteristics that are expressed, such as hair color or height. This approach examines how the combination of alleles, dominant or recessive, manifests as physical traits in organisms. The genotypic perspective targets the genetic makeup or allele combinations within an organism's DNA. While studying Mendelian genetics, geneticists pay close attention to how these genotypes determine the phenotypes, and how they are passed from parents to offspring following Mendel's laws of inheritance.
In-depth research over the years, including human genome sequencing, has equipped scientists to predict heritable traits by analyzing parental genotypes or phenotypes. However, it's essential to consider that most diseases show a multigenic pattern of inheritance and can be influenced by environmental factors, making heredity predictions complex. For some single-gene disorders, genetic testing can provide a clearer probability of inheritance.