Every individual possesses two alleles for a trait, but only one is passed on to a gamete (sperm or egg).
Genetics is not just about stability; it is also about change. occurs through recombination during reproduction and through mutations —random changes in the DNA sequence. While some mutations are harmful, others provide the raw material for evolution, allowing species to adapt to changing environments over generations. Modern Applications and Ethics Principles of Genetics
The "Central Dogma" of molecular biology describes the flow of this information: DNA is transcribed into RNA, which is then translated into proteins. This process determines an organism's (observable traits) based on its genotype (genetic makeup). Genetic Variation and Mutation Every individual possesses two alleles for a trait,
Some alleles are dominant and will mask the expression of recessive alleles. The Role of DNA and Chromosomes While some mutations are harmful, others provide the
The study of genetics began in the mid-19th century with Gregor Mendel’s experiments on pea plants. Mendel established the , which remain the bedrock of the field:
While Mendel identified the patterns, it wasn't until the 20th century that scientists identified as the physical carrier of this information. DNA is organized into structures called chromosomes . A gene is a specific segment of DNA that contains the instructions for building proteins—the workhorses of the body.