Question

Match the following:

a.	Zygotene	1.	Crossing over
b.	Pachytene	2.	Chiasmata
c.	Diplotene	3.	Open, long, thin thread
d.	Leptotene	4.	Synepsis

1. a - 4, b - 3, c - 1, d - 2
2. a - 4, b - 1, c - 3, d - 2
3. a - 4, b - 1, c - 2, d - 3
4. a - 4, b - 3, c - 2, d - 1

Answer 1

Correct Answer - Option 3 : a - 4, b - 1, c - 2, d - 3

The correct answer is a - 4, b - 1, c - 2, d - 3.

Explanation:

• Zygotene: 
  • Zygotene is the second stage in the Prophase-I of Meiosis that takes place after the completion of the leptotene.
  • Zygotene is distinguished by the synapsis, or pairing, of homologous chromosomes to form a bivalent chromosome.
  • In this phase, Homologous chromosomes pair up. This pairing is done in such a way that the genes for the same character on both chromosomes are exactly opposite to each other. This association process is known as synapsis.
• Pachytene: 
  • This is the stage immediately following zygotene in which the chromosomes become twisted spirally around each other and cannot be distinguished separately.
  • Crossing-over occurs during meiosis at the pachytene stage when homologous chromosomes are completely paired.
• Diplotene: 
  • It is the stage of the longest duration of all.
  • Diplotene is distinguished by chiasmata.
  • In this phase, Recombined homologous chromosomes of the bivalents get separated and form chiasmata (X-shaped structures).
  • The formation of chiasmata is necessary for the separation of homologous chromosomes that have undergone the process of crossing over.
• Leptotene:  
  • It is known to be the very fast stage of meiotic division.
  • The leptotene stage is the stage at which the chromosomes that were duplicated in the previous interphase of cell division begin to form open, long, thin thread-like structures from the previously diffused state