Question

During which stages (or prophase I sub stages) of meiosis do you expect to find the bivalents and DNA replication respectively?

• A. Pachytene and interphase (between two meiotic divisions)
• B. Pachytene and interphase (just prior to prophase I)
• C. Pachytene and S phase (of interphase just prior to prophase I)
• D. Zygotene and S phase (of interphase prior to prophase I)

Answer 1

The correct option is D Zygotene and S phase (of interphase prior to prophase I)

In bivalent formation of chromosomes during meiosis, the homologous chromosomes are arranged in pairs. This phenomenon of homologous pairing is called synapsis and it occurs during zygotene stage.
DNA replication occurs during S phase or synthetic phase which is the second phase of interphase.
So the correct option is "d".