Question

1. how does sexual reproduction contribute to genetic variation? 2. a current challenge for doctors involves the bacterial strain clostridioides difficile, which no longer responds to traditional antibiotic treatments. explain why this particular strain of bacteria is resistant to antibiotic treatment.

Explanation:

1. Sexual reproduction involves the combination of genetic material from two parents. During meiosis, crossing - over occurs between homologous chromosomes, which exchanges genetic segments. Also, independent assortment of chromosomes during meiosis leads to different combinations of maternal and paternal chromosomes in gametes. When gametes fuse during fertilization, unique genetic combinations are formed, contributing to genetic variation.
2. Clostridioides difficile may be resistant to traditional antibiotic treatments due to several factors. It can acquire resistance genes through horizontal gene transfer from other bacteria. Mutations in its own genes can also lead to changes in the target sites of antibiotics, making the antibiotics ineffective. Additionally, some strains may produce biofilms that protect the bacteria from antibiotics by preventing their access to the bacterial cells.

Answer:

1. Sexual reproduction contributes to genetic variation through crossing - over during meiosis, independent assortment of chromosomes during meiosis, and the fusion of gametes during fertilization.
2. Clostridioides difficile is resistant to antibiotic treatment due to horizontal gene transfer, gene mutations, and biofilm production.