Question

Match the following: 

List-I (Subphase of Prophase-I)	List-II (Specific Characters)
A. Diakinesis	I. Synaptonemal complex formation
B. Pachytene	II. Completion of terminalization of chiasmata
C. Zygotene	III. Chromosome looks like thin threads
D. Leptotene	IV. Appearance of recombination nodule

• A. A-I, B-III, C-II, D-IV
• B. A-II, B-I, C-IV, D-III
• C. A-II, B-IV, C-III, D-I
• D. A-II, B-IV, C-I, D-III

Hint:

Leptotene = thin threads, Zygotene = synapsis, Pachytene = crossing over, Diakinesis = terminalization of chiasmata.

Answer 1

The Correct Option is D

Concept: Prophase-I of meiosis is the longest and most complex phase. It consists of five successive stages: \[ \text{Leptotene} \rightarrow \text{Zygotene} \rightarrow \text{Pachytene} \rightarrow \text{Diplotene} \rightarrow \text{Diakinesis} \] Each stage has unique cytological features.

Step 1: Match Leptotene. Chromosomes first become visible as long thin threads. Therefore: \[ D \rightarrow III \]

Step 2: Match Zygotene. Homologous chromosomes pair through synapsis. The synaptonemal complex forms during this stage. Therefore: \[ C \rightarrow I \]

Step 3: Match Pachytene. Crossing over occurs and recombination nodules appear. Therefore: \[ B \rightarrow IV \]

Step 4: Match Diakinesis. Terminalization of chiasmata becomes complete. Therefore: \[ A \rightarrow II \]

Step 5: Final matching. \[ A-II,\; B-IV,\; C-I,\; D-III \] Hence option (D) is correct.