Lampbrush chromosomes occur during which of the following stages?

In which of the following stages is the chromosome thin and like a long thread?

Which of the following statement$(s)$ is/are not correct about meiosis?
$I.$ Meiosis involves pairing of homologous chromosomes and recombination between them.
$II.$ Two diploid cells are formed at the end of meiosis-$II$.
$III.$ Meiosis involves two sequential cycles of nuclear and cell division called meiosis-$I$ and meiosis-$II$,but only a single cycle of $DNA$ replication.
$IV.$ Meiosis-$I$ is initiated after the parental chromosome replication which produces identical sister chromatids at the $S$-phase.
The correct option is

The diagram shows a bivalent at prophase-$I$ of meiosis. Which of the four chromatids can cross over?

In which stage of Prophase-$I$ do chromosomes condense and appear as thin,thread-like structures?

The pairing of homologous chromosomes occurs in ..........