Q.11 Separation of two different alleles from each other during gamete formation in a heterozygote follows:
1. Law of unit factors
2. Law of segregation
3. Law of dominance
4. Law of independent assortment
Allele Separation Follows Law of Segregation
In Mendelian genetics, alleles separate during meiosis in heterozygotes to ensure gametes carry one allele each. The correct answer is 2. Law of segregation.
Correct Answer
Mendel’s Law of Segregation states that during gamete formation in a heterozygote (Aa), the two alleles separate so each gamete receives only one allele randomly, explaining 3:1 phenotypic ratios in F2 generations. This occurs in meiosis I when homologous chromosomes segregate, ensuring genetic diversity.
Option Explanations
1. Law of Unit Factors (Incorrect)
The Law of Unit Factors (or Unit Characters) posits that traits are inherited as discrete units (genes) rather than blending, but it does not describe allele separation during gametogenesis.
2. Law of Segregation (Correct)
In heterozygotes, paired alleles (one dominant, one recessive) segregate during meiosis, with each gamete getting a single allele at random, forming the basis of monohybrid crosses.
3. Law of Dominance (Incorrect)
The Law of Dominance states that one allele masks the effect of the recessive allele in heterozygotes, determining phenotype but not addressing gamete formation or allele separation.
4. Law of Independent Assortment (Incorrect)
This law applies to dihybrid crosses, where alleles of different genes assort independently during gamete formation, not the separation of alleles for a single gene.
