Final answer:
Telomeres are the short repeats of DNA on the ends of eukaryotic chromosomes, which contain repetitive, noncoding sequences to protect chromosomes during cell division. They are elongated by the enzyme telomerase, which has a built-in RNA template, ensuring chromosome integrity.
Step-by-step explanation:
The short repeats of DNA on the ends of eukaryotic chromosomes are known as telomeres. Telomeres consist of noncoding repetitive sequences which act to protect the coding sequences of DNA from being lost during cell division. Contrary to other options, telomeres do not code for a particular gene and are crucial in maintaining the integrity of chromosomes. In humans, the telomere sequence is a six base-pair repeat of TTAGGG, occurring 100 to 1000 times.
Role of Telomerase
The enzyme that helps to maintain these telomeres is called telomerase. This enzyme contains both a catalytic part and a built-in RNA template, which it uses to elongate the telomere sequences on the DNA. This prevents the telomere regions from shortening with each cell division, thus protecting the genetic information within the chromosomes.