Question

Telomeres are repetitive nucleotide sequences located at the termini of linear chromosomes of most eukaryotic organisms. The telomeres are usually rich in which of the following nucleotide?

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

Answer 1

The correct option is B Guanine

Telomere are long stretches of repeating non-coding DNA sequences at the ends of the DNA strand. They protect the ends of DNA and prevent DNA strands from shortening or attaching to other molecules by masking the chromosome. Telomeres account for the lost bits of DNA at the ends of chromosomes during DNA replication. Since DNA polymerase moves along the template strand in the 5'--> 3' direction, some of the 5' end of the template strand will not be replicated. This results in the incomplete ends. However, telomeres are usually very long, ranging from 400 to 600 base pairs in yeast to many kilobases in humans. They are made of six to eight base pair long repeats which are usually rich with guanine bases.

Therefore, the correct answer is option B.