5. Describe Mendel's 1^st law of genetics?' (Law of segregation)

Mendel's First Law of Genetics, also known as the Law of Segregation, is a fundamental principle of inheritance formulated by Gregor Mendel in the 19th century. This law states that during the formation of gametes (sperm and egg cells), the two alleles for a given trait separate, or segregate, so that each gamete carries only one allele for each trait.<br /><br />Key points of the Law of Segregation include:<br /><br />1. **Allele Pairs**: Each organism inherits two alleles for each trait, one from each parent. These alleles can be either identical (homozygous) or different (heterozygous).<br /><br />2. **Separation During Gamete Formation**: During meiosis, the process of cell division that produces gametes, the paired alleles segregate so that each gamete receives only one allele from each pair.<br /><br />3. **Random Fertilization**: When gametes unite during fertilization, the offspring inherit one allele from each parent, restoring the pair of alleles for each trait.<br /><br />4. **Predictable Ratios**: The segregation of alleles leads to predictable ratios of traits in the offspring, which Mendel observed in his experiments with pea plants. For example, when crossing two heterozygous individuals (Aa x Aa), the expected genotypic ratio is 1:2:1 (AA:Aa:aa), and the phenotypic ratio is typically 3:1 if one allele is dominant over the other.<br /><br />Mendel's Law of Segregation laid the groundwork for understanding how traits are inherited and remains a cornerstone of classical genetics.