When does pairing/synapsis of homologous chromosomes (bivalent formation) occur in meiosis ?
When does pairing/synapsis of homologous chromosomes (bivalent formation) occur in meiosis ?
The correct option is B Pachytene
Prophase I of meiosis I is divided into a series of substages which are named according to the appearance of chromosomes. The five stages are: leptotene, zygotene, pachytene, diplotene and diakinesis. A bivalent, also known as a tetrad (because of involvement of four chromatids) sometimes, is the association of a pair of homologous chromosomes physically held together by at least one DNA crossover. The formation of a bivalent occurs during the pachytene stage. During this stage, chromosomal condensation makes it possible for the chromosomes to be viewed under the microscope. The homologous chromosomes, also known as bivalent chromosomes or bivalents, pair up side-by-side along the length of the chromosomes.
Prophase I of meiosis I is divided into a series of substages which are named according to the appearance of chromosomes. The five stages are: leptotene, zygotene, pachytene, diplotene and diakinesis. A bivalent, also known as a tetrad (because of involvement of four chromatids) sometimes, is the association of a pair of homologous chromosomes physically held together by at least one DNA crossover. The formation of a bivalent occurs during the pachytene stage. During this stage, chromosomal condensation makes it possible for the chromosomes to be viewed under the microscope. The homologous chromosomes, also known as bivalent chromosomes or bivalents, pair up side-by-side along the length of the chromosomes.
