'Generally, gametes produced by an organism will not be identical.' Which of the following does NOT influence this genetic variability of gamete formation? (A) Mutation (B) Sex linkage (C) Independent assortment of alleles (D) Crossing over in homologous chromosomes - HSC - SSCE Biology - Question 15 - 2004 - Paper 1

To determine which option does not influence genetic variability in gametes, we need to understand what each term means:

• Mutation: This is a change in the DNA sequence, which can introduce new alleles into a population, influencing genetic variability.
• Sex linkage: This refers to genes located on sex chromosomes, affecting traits in a manner that leads to different expressions in males and females, thus influencing genetic variability.
• Independent assortment of alleles: This principle states that alleles for different traits segregate independently during gamete formation, leading to genetic variability.
• Crossing over in homologous chromosomes: This process occurs during meiosis, where homologous chromosomes exchange segments, leading to new combinations of alleles and thus increasing variability in gametes.

Among these options, (B) Sex linkage is the correct answer, as it does not contribute to overall genetic variability in the formation of gametes in the same manner as the others.