Sister chromatids __________.

• A. are involved in mitosis only
• B. are pairs of chromosomes, one of which comes from the father and one of which comes from the mother
• C. have the same gene loci but may have different alleles of some genes
• D. are involved in meiosis only
• E. are identical copies of each other formed through DNA synthesis

Answer: (E)

Verified step by step guidance

1. Understand the definition of sister chromatids: Sister chromatids are identical copies of a single chromosome that are connected by a centromere. They are formed during the DNA replication phase of the cell cycle, specifically during the S phase.
2. Differentiate between sister chromatids and homologous chromosomes: Sister chromatids are identical copies of the same chromosome, whereas homologous chromosomes are a pair of chromosomes, one inherited from each parent, that have the same gene loci but may have different alleles.
3. Identify the role of sister chromatids in cell division: Sister chromatids are involved in both mitosis and meiosis. During mitosis, they are separated into two new nuclei, ensuring each daughter cell receives an identical set of chromosomes. In meiosis, they are separated during the second division (meiosis II) to form gametes.
4. Clarify the genetic composition of sister chromatids: Since sister chromatids are formed by the replication of a single chromosome, they contain identical genetic information, including the same alleles at each gene locus.
5. Conclude with the correct statement: Sister chromatids are identical copies of each other formed through DNA synthesis, which occurs during the S phase of the cell cycle.