List-I (Events) |
List-II (Prophase-I) |
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A. | Chromosomes start pairing together to form synaptonemal complex | I. | Pachytene |
B. | Chromosomes visible under light microscope and compaction continues | II. | Zygotene |
C. | Four chromatids of bivalent chromosomes become distinct and recombinant nodules appear | III. | Diplotene |
D. | Dissolution of synaptonemal complex | IV. | Leptotene |
List-I (Cell Cycle) | List-II (Events) | ||
A. | \(G_1\) phase | I. | Cell is metabolically active but no proliferation until required |
B. | S phase | II. | Replication of DNA |
C. | \(G_0\) stage | III. | Synthesis of proteins |
D. | \(G_2\) phase | IV. | Cell is metabolically active and grows continuously |
List I (Sub Phase of Prophase I) |
List II (Specific characters) |
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A. | Diakinesis | I. | Synaptonemal complex formation |
B. | Pachytene | II. | Completion of terminalisation of chiasmata |
C. | Zygotene | III. | Chromosomes look like thin threads |
D. | Leptotene | IV. | Appearance of recombination nodules |
Statement I: | Chromosomes become gradually visible under light microscope during leptotene stage. |
Statement II: | The begining of diplotene stage is recognized by dissolution of synaptonemal complex. |
Assertion (A): | Meiosis is the mechanism by which conservation of specific chromosome number of each species is achieved across generations in sexually reproducing organisms. |
Reason (R): | Meiosis results in reduction of chromosome number by half in gametes. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
1. | Metaphase I | 2. | Metaphase II |
3. | Anaphase I | 4. | Anaphase II |
Statement I: | At Metaphase I the chromosomes align at the equator and the microtubules from opposite poles of the spindle get attached to the kinetochores of sister chromatids. |
Statement II: | At metaphase II the bivalent chromosomes align on the equatorial plate and microtubules from the opposite poles of the spindle attach to the kinetochore of homologous chromosomes. |
1. | Statement I is correct and Statement II is incorrect. |
2. | Statement I is incorrect and Statement II is incorrect. |
3. | Statement I is correct and Statement II is correct. |
4. | Statement I is incorrect and Statement II is correct. |