Explain the essence of Mendel’s first law. Formulate Mendel’s second law.

1. Explain the essence of Mendel’s first law. 2. Formulate Mendel’s second law. 3. What is the difference between F1 and F2 in monohybrid crossing 4. Why are alleles always paired?

1. If you cross 2 organisms that differ in only one trait (AA + aa), then all offspring (F1) will have a dominant gene (Aa).
2. When F1 organisms are crossed, the new offspring (F2) differ in phenotype as 3: 1, in genotype 1: 2: 1 (1 AA: 2Aa: 1aa).
3. F1: only the dominant gene appears. F2: because both parents have both a dominant and a recessive gene, there is a distribution of traits both by phenotype and by genotype.
4. Because in a diploid cell there are two identical chromosomes, then the alleles are paired.