Question

Telomeres are present in:
(A). E. coli chromosome
(B). Yeast Chromosome
(C). Human Chromosome
(D). Molds chromosome
Choose the correct answer from the options given below:

• A. (A), (B) and (D) only.
• B. (A), (B) and (C) only.
• C. (A), (B), (C) and (D).
• D. (B), (C) and (D) only.

Hint:

Telomeres are a structural feature exclusive to linear chromosomes.
Circular genomes (like those of bacteria, mitochondria, and plasmids) do not have ends and therefore lack telomeres.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Telomeres are specialized repetitive nucleotide sequences located at the terminal ends of linear chromosomes.
They protect the chromosome ends from degradation and prevent them from fusing with other chromosomes during replication.

Step 2: Detailed Explanation:
- Linear Chromosomes: Eukaryotes, including unicellular yeast (B), humans (C), and molds/fungi (D), possess linear chromosomes. Therefore, they require telomeres at their ends to resolve the "end-replication problem."
- Circular Chromosomes: Prokaryotes like E. coli (A) possess a single circular chromosome. Because circular DNA has no ends, it does not suffer from the end-replication problem and does not possess telomeres.
Thus, telomeres are present in yeast, human, and mold chromosomes.

Step 3: Final Answer:
The correct option is (B), (C) and (D) only, corresponding to option (D).