6
Given below are two statements regarding the number of possible rooted or unrooted trees for a given number of operational taxonomic units (OTUs):
Statement (I) : For two OTUs, only two trees are possible.
Statement (II) : For three or more than three OTUs, the number of possible rooted trees is always less than the number of
possible unrooted trees.
In light of the above statements, choose the most appropriate answer from the options given below.
EXPLANATION
Molecular Phylogenetics
- Number of Rooted and Unrooted Trees:
- Statement (I): For two OTUs, only two trees are possible. $\implies$ False.
- For $n = 2$ taxa, there is exactly 1 unrooted tree and 1 rooted tree.
- Statement (II): For three or more than three OTUs, the number of possible rooted trees is always less than the number of possible unrooted trees. $\implies$ False.
- For $n$ taxa, the number of rooted trees ($N_r$) is strictly greater than unrooted trees ($N_u$):
- For $n = 3$: $N_u = 1$, whereas $N_r = 3$.
- For $n = 4$: $N_u = 3$, whereas $N_r = 15$.
- The number of rooted trees is always larger by a factor of $(2n - 3)$.
- Conclusion: Both Statement (I) and Statement (II) are false (Option 2).
Correct option: (2) Both Statement (I) and Statement (II) are false.
Explanation not matching this question?
क्या व्याख्या इस प्रश्न से मेल नहीं खा रही?
Report
Want to practice this paper in exam conditions?
क्या आप परीक्षा जैसे माहौल में अभ्यास करना चाहते हैं?
Test yourself in 5-question batch format with timer and hidden answers.
5-प्रश्नों के बैच फॉर्मैट, टाइमर और छिपे उत्तरों के साथ खुद को परखें।
Start Practice Mode →
प्रैक्टिस टेस्ट मोड शुरू करें →