Final answer:
In the G1 phase of the meiotic cell cycle of a diploid organism with a haploid number of 13, there will be 26 chromatids, as the chromosomes have not yet duplicated.
Step-by-step explanation:
The subject of this question is Biology, specifically concerning the meiotic cell cycle in a diploid organism with a haploid number of 13. During the G1 phase of the meiotic cell cycle, each chromosome consists of only one chromatid, as chromosome duplication has not yet occurred. Therefore, for a diploid organism with a haploid number of 13, there would be 26 chromatids present during the G1 phase (13 pairs of homologous chromosomes).
Explanation: In diploid organisms, cells contain two sets of chromosomes, one from each parent. Before DNA replication occurs in the S phase, each chromosome is unduplicated and has only one chromatid. Thus, in the G1 phase of meiosis, a diploid organism with a haploid number (n) of 13 will have 2n = 26 chromosomes, each with one chromatid, totaling 26 chromatids