Question

Prior to meiosis I, the cell undergoes a round of ______ _____ called interphase I. Each replicated chromosome consists of two ______ ______ joined at the center.

Answer 1

Before meiosis I, the cell goes through interphase I where DNA replication occurs, resulting in duplicated chromosomes that consist of two sister chromatids joined at the centromere. This phase is critical for the correct distribution of genetic material during subsequent stages of meiosis.

Step-by-step explanation:

Prior to meiosis I, the cell undergoes a round of cell division called interphase I. During this phase, each replicated chromosome consists of two sister chromatids joined at the center.

The interphase I includes three stages: The G1 phase or first gap phase, where cell growth occurs; the S phase or synthesis phase, where DNA replication occurs, resulting in the formation of two identical copies of each chromosome which are called sister chromatids; and the G2 phase or second gap phase, which is the final phase of interphase, where the cell prepares for meiosis.

Each sister chromatid is connected to its duplicate by cohesin proteins at a region called the centromere. The centromeres are highly condensed, making the connection between the sister chromatids visible under a light microscope. This replication during the S phase is critical as it allows for the sister chromatids to be separated into different cells during meiosis II, ultimately leading to the formation of four new haploid gametes.