Mendel's first law is the law of:

**The reasoning** Gregor Mendel discovered several fundamental laws of inheritance. His **First Law** (also called the Law of Segregation) states that: *During gamete formation (making sperm or egg cells), the two alleles (gene variants) for each trait separate, so each gamete carries only ONE allele for each gene.* Think of it this way: If you're heterozygous Tt (tall), your body doesn't pass "Tt" to your child. Instead, the T and t **segregate** (separate) during meiosis, so each sperm/egg gets either T *or* t — never both. **Why the wrong options tempt you** - **Independence** is Mendel's *Second* Law (different genes assort independently) - **Dominance** describes how one allele masks another (Tt looks tall), but it's not called Mendel's First Law - **Heredity** is the general concept of traits passing down, too broad to be a specific law **Quick takeaway** Remember: **"FIRST = SEGREGATION"** — allele pairs split up during gamete formation, one allele per sex cell. This is the foundation of everything else in genetics!