Genetics is a high-scoring section in Gaokao biology. Understanding key theorems like Mendel's laws and Hardy-Weinberg equilibrium is essential for quick problem solving. These fundamental principles help predict inheritance patterns and population genetics, making them crucial for exam success.
Mendel's Law of Segregation is fundamental for understanding inheritance. Each trait is controlled by two alleles that separate during meiosis, with each gamete receiving one allele. During fertilization, alleles reunite to form the offspring genotype. This law explains why traits can skip generations and helps predict inheritance patterns using Punnett squares.
The Law of Independent Assortment explains how genes on different chromosomes are inherited independently. When an organism has two traits controlled by genes on separate chromosomes, each trait is inherited separately, producing four types of gametes in equal proportions. This results in the classic 9:3:3:1 phenotypic ratio in the F2 generation of a dihybrid cross.
Hardy-Weinberg Equilibrium describes how allele frequencies remain constant in populations under ideal conditions. The formula p² + 2pq + q² = 1 represents genotype frequencies, where p and q are allele frequencies. For Gaokao problems, typically start with the recessive phenotype frequency to calculate q, then determine p, and finally calculate all genotype frequencies.
Success in Gaokao genetics requires systematic problem-solving strategies. First, identify the inheritance pattern by looking for clues like hidden traits appearing, which indicates recessive inheritance. Then apply the appropriate method - Punnett squares for crosses or Hardy-Weinberg for populations. Break complex problems into simpler parts and always verify your answers for reasonableness. Practice these patterns regularly for quick recognition during exams.