Final answer:
A cell with 18 chromatids would have 9 duplicated chromosomes since each duplicated chromosome consists of two sister chromatids. Answer (B) is correct.
Step-by-step explanation:
If a cell has 18 chromatids, it implies that it has undergone DNA replication but has not yet undergone cell division. During cell division, chromatids are distributed into separate cells. A chromatid is one copy of a duplicated chromosome, which is connected to the other copy by a single centromere. As each duplicated chromosome consists of two sister chromatids, to determine the number of duplicated chromosomes when given the number of chromatids, you simply divide the number of chromatids by two.
Therefore, if there are 18 chromatids in a cell, the number of duplicated chromosomes is 18 divided by 2.
The correct answer is: (B) 9 duplicated chromosomes.
Reviewing some related concepts:
A diploid cell has twice the number of chromosomes as a haploid cell.
Chromosomes are crucial for ensuring that each cell receives the proper amount of DNA during cell division.
In humans, each cell typically contains 46 chromosomes, which after DNA replication results in 92 chromatids.