Meiosis is preceded by interphase which consists of the G1 phase (growth), the S phase ( DNA replication), and the G2 phase. During prophase I, the homologous chromosomes condense and become visible as the x shape we know, pair up to form a tetrad, and exchange genetic material by crossing over.
What happens to homologous chromosomes during interphase?
Chromosomes that are duplicated during interphase 1 remain sister chromatids. Homologous chromosomes join and form pairs. The membrane surrounding the nucleus breaks. … Sister chromatids of each duplicated chromosome are pulled apart and move to opposite ends of the cell ( or opposite polls).
Where does homologous chromosomes occur?
In each somatic cell of the organism, the nucleus contains two copies of each chromosome, called homologous chromosomes. Somatic cells are sometimes referred to as “body” cells. Homologous chromosomes are matched pairs containing the same genes in identical locations along their length.
Why G1 and G2 are genetically identical?
In G1, each chromosome is a single chromatid. In G2, after DNA replication in S phase, as cell enter mitotic prophase, each chromosome consists of a pair of identical sister chromatids, where each chromatid contains a linear DNA molecule that is identical to the joined sister.