A replicated chromosome is composed of two identical halves connected at the centromere; each half is called a

A replicated chromosome is composed of two identical halves connected at the centromere; each half is called a

• A. Chromatid
• B. Chromosome
• C. Chromatin
• D. Centromere

Answer: (A)

When a chromosome is replicated, it becomes two identical copies held together at the centromere. Each of these copies is called a chromatid, and together they form a replicated chromosome with two chromatids joined at the centromere. This term specifies one of the two identical halves. The other terms don’t fit: chromatin is the less condensed form of DNA in the nucleus, the centromere is the narrowed region where chromatids attach, and a chromosome can refer to the whole structure, not just one half. So the best label for each half is chromatid.

When a chromosome is replicated, it becomes two identical copies held together at the centromere. Each of these copies is called a chromatid, and together they form a replicated chromosome with two chromatids joined at the centromere. This term specifies one of the two identical halves. The other terms don’t fit: chromatin is the less condensed form of DNA in the nucleus, the centromere is the narrowed region where chromatids attach, and a chromosome can refer to the whole structure, not just one half. So the best label for each half is chromatid.