Question

Synaptonemal complex is formed during
A. Meiosis
B. Amitosis
C. Mitosis
D. Cytokinesis

Answer 1

Hint: The Synaptonemal complex is a tripartite structure. It consists of two parallel and a central core element. It was described by Montrose J. Moses in 1956 and was demonstrated in the primary spermatocytes of crayfish.

Complete answer:
Synaptonemal complex is a protease structure and it functions to mediate the process of synapsis and recombination in the eukaryotic cells. The Synaptonemal complex primarily functions as a scaffold to allow interacting chromatids to undertake their crossover activities.
The Synaptonemal complex is formed between the homologous chromosomes between two pairs of sister chromatids during the process of meiosis. It is seen in the pachytene stage of the first meiotic prophase. After the pachytene stage of meiosis, the complex is disassembled and further it cannot be identified. The formation of the Synaptonemal complex shows the pairing or synapsis of the homologous chromosomes. It also brings about the process of recombination.
Amitosis is the process of direct cell division. In this process, the cell divides by proliferation or binary division. In ciliates, the macronucleus divides mitotically. The process of amitosis causes the random distribution of parental alleles. It does not involve the process of spindle formation and pairing of homologous chromosomes and this process does not involve the synaptonemal complex.
Mitosis is the equatorial division of a parental cell and it produces two daughter cells. It mostly occurs in the somatic cells. In this process, the daughter cells are genetically identical to the parents. The synaptonemal complex is responsible for recombination and cross over between the sister chromatids which does not take place in the mitotic process.
The process of cell division during which the cytoplasm of the parental cell divides into two daughter cells is known as cytokinesis. It begins at the latter stages of the cell division of mitosis and meiosis. During this process, the spindle apparatus is divided and transports duplicated chromatids into the cytoplasm of the separating daughter cells.

Hence, the correct answer is option (A).

Note: Synaptonemal complex is a tripartite structure consisting of two lateral elements and a single central element. It is made up of protein and is formed between the two homologous sister chromatids that is seen during the process of meiotic cell division. This structure is found in the pachytene stage of first meiotic division.