AI-generated explanation. Check against your textbook.
Explanation:
Option 2 is correct. Plasmogamy means the fusion of cytoplasm (protoplasm) of two gametes, which may be motile or non-motile. Karyogamy (not option 1) is the fusion of the nuclei. Option 3 is incorrect because saprophytes feed on dead organic matter, whereas organisms that depend on living plants are parasites. Option 4 is incorrect because nitrogen fixation in cyanobacteria occurs in specialized cells called heterocysts, not sheath cells.
🧠 Did You Know?
In fungi, plasmogamy often occurs first, followed by karyogamy to form a diploid nucleus.
💡 NCERT Memory Line:
Plasmogamy = fusion of cytoplasm; Karyogamy = fusion of nuclei.
Match Column-I with Column-II.
Choose the correct answer from the options given below:
AI-generated explanation. Check against your textbook.
Explanation:
The correct choice is 4: A-III, B-IV, C-II, D-I. In NCERT-based matching questions, each item in Column-I pairs with the most appropriate description in Column-II. The sequence in option 4 aligns each A, B, C, D with the description that NCERT identifies as its corresponding feature or step, while the other options misplace one or more pairings, leading to incorrect matches. This strict one-to-one correspondence is the key principle in such questions.
🧠 Did You Know?
NCERT emphasizes clear pairings between processes or structures in biology, helping students solidify conceptual links rather than memorize isolated facts.
💡 NCERT Memory Line:
Match each item in Column-I with the most appropriate description in Column-II; only one option gives all correct pairings.