List the events which occurs during …

Zygotene

The zygotene stage, otherwise called zygonema, from Greek words signifying "matched threads", happens as the chromosomes approximately line up with one another into homologous chromosome pairs. In some organisms, this is known as the bouquet stage as a result of the manner in which the telomeres bouquet toward one side of the core. At this stage, the synapsis of homologous chromosomes happens, encouraged by gathering of the central component of the synaptonemal complex. Pairing is achieved in a zipper-like style and may begin at the centromere (pro-centric), at the chromosome ends (terminal), or at some other portion. Individuals of a pair are equivalent long and in the position of the centromere. Therefore, pairing is very specific and definite. The paired chromosomes are known as bivalent or quadruplicate chromosomes.

Pachytene

The pachytene stage, otherwise called pachynema, from Greek words signifying "thick threads". At this point, a quadruplicate of the chromosomes has framed known as a bivalent. This is the phase when homologous recombination, including chromosomal hybrid (traverse), happens. At this stage, the Non-sister chromatids of homologous chromosomes may exchange segments over regions of homology. 

Anaphase I

Kinetochore microtubules become short, pulling homologous chromosomes (which comprise of a couple of sister chromatids) to opposite poles. Nonkinetochore microtubules extend, pushing the centrosomes separated apart. The cell stretches for division down the center. Unlike in mitosis, just the cohesin from the chromosome arms is degraded while the cohesin encompassing the centromere stays secured. This enables the sister chromatids to stay together while homologs are segregated.