Zygotene stage of meiosis is characterised by pairing of homologous chromosomes (synapsis). This pairing is brought about in a zipperlike fashion and may start at centromere, at chromosome ends or at any other position. Two homologous chromosomes are called bivalent while they are pairing during meiosis. The homologous chromosomes break their connection and separate out during Anaphase- 1 of meiosis. The process of separation is named as disjunction. Synergids are elongated cells present at the micropylar end of the embryo sac.