Final answer:
Programmed DSBs occur during Meiosis I in germ cells to facilitate homologous recombination, enhancing genetic diversity through crossover events.
Step-by-step explanation:
The programmed creation of double-strand breaks (DSBs) occurs during meiosis in germ cells. This is captured in option B. Specifically, during the first division of meiosis (Meiosis I), during a stage known as prophase I, the process of homologous recombination is facilitated. Here, homologous chromosomes pair up in synapsis and may undergo DNA breakage followed by an exchange of alleles between the chromosomes and subsequent ligation to reseal the DNA. This crossover event contributes to genetic variation by combining maternal and paternal alleles in new ways within the chromosomes of sperm and egg cells, ensuring genetic diversity among offspring.
Programmed creation of double-strand breaks (DSBs) occurs during meiosis in germ cells. This process, known as homologous recombination, facilitates genetic variation. In meiosis I, homologous chromosomes pair up and exchange genetic material through crossovers. This exchange of alleles between chromatids results in the formation of recombinant chromosomes, which contribute to genetic diversity. Meiosis II then separates the chromatids, resulting in four haploid cells with unique combinations of maternal and paternal chromosomes.