Question

The telomeres of eukaryotic chromosomes consist of short sequences of

• A. Cytosine rich repeats
• B. Adenine rich repeats
• C. Guanine rich repeats
• D. Thymine rich repeats

Answer 1

Answer: (C)

Guanine rich repeats

Answer 2

Telomeres are repetitive sequences of nucleotides found at the ends of linear chromosomes in the majority of eukaryotic organisms. Typically, these telomeric DNA sequences consist of short sequences rich in guanine and conclude with a single-stranded G-rich overhang, spanning about 150 to 200 nucleotides in length. Telomerase, a specialized enzyme, is responsible for synthesizing this G-rich strand. It utilizes a small section of its RNA component as a template and the 3-OH end of the chromosome as a starting point. In vertebrates, the specific sequence in telomeres is TTAGGG. Unlike eukaryotes, most prokaryotes lack this linear chromosomal structure and, as a result, do not possess telomeres. Consequently, it's important to note that eukaryotic telomeres primarily consist of short sequences rich in guanine repeats and not in cytosine, adenine, and thymine repeats. Therefore, option C is the correct one, while the other options are incorrect.