make this into one sentence, "In interphase, the starting cell duplicates its chromosomes. This means that the number of chromosomes remains the same, but the number of chromatids doubles. In a human cell after interphase, you would expect the same number of chromosomes as before, but twice as many chromatids."

During interphase, the starting cell duplicates its chromosomes, resulting in the same number of chromosomes and twice as many chromatids in a human cell after interphase.

In interphase, the starting cell duplicates its chromosomes, resulting in the same number of chromosomes but twice as many chromatids in a human cell after interphase.

During interphase, the starting cell undergoes chromosomal duplication, resulting in the preservation of the same number of chromosomes, while the quantity of chromatids increases twofold, thus, after interphase in a human cell, the number of chromosomes is anticipated to remain unchanged, but the number of chromatids is expected to double.