Final answer:
Genetic variability is attained in sexual reproduction through meiosis, where crossover and chromosome assortment generate unique gametes, and fertilization, where these gametes combine to form a genetically diverse diploid organism.
Step-by-step explanation:
The variability of genetic information is attained through meiosis and fertilization. During meiosis, which includes two nuclear divisions, homologous chromosomes pair up and exchange genetic material through a process called crossover. This exchange of genetic material between non-sister chromatids and the subsequent separation of homologous chromosomes during meiosis I leads to a reduction in the ploidy level from diploid to haploid, producing genetically unique gametes. Fertilization, on the other hand, involves the fusion of these haploid gametes from two parents, restoring the diploid condition and combining varied genetic material from both parents into a single new organism.
Through the random assortment of chromosomes and crossover events during meiosis, as well as the random selection of which gametes will participate in fertilization, genetic diversity is achieved. This ensures that offspring contain a mix of alleles from both parents, leading to the potential for new combinations of traits. In summary, the correct answer to the student's question is B) Meiosis shuffles genetic material, and fertilization combines genetic material from two parents.