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 contributes to genetic variation through processes like meiosis - crossing - over during prophase I exchanges genetic material between homologous chromosomes, independent assortment of chromosomes during meiosis I results in different combinations of parental chromosomes in gametes, and random fertilization where any sperm can fertilize any egg, creating unique genetic combinations.
2. The Clostridioides difficile strain is resistant to traditional antibiotic treatments likely due to genetic mutations that confer resistance. These mutations can be passed on to daughter cells during bacterial reproduction. Also, over - use and misuse of antibiotics in the past may have selected for resistant strains, as non - resistant bacteria were killed off while resistant ones survived and multiplied.

Answer:

1. Through crossing - over in meiosis, independent assortment of chromosomes, and random fertilization.
2. Due to genetic mutations and selection pressure from antibiotic use.