How does the enzyme telomerase meet the challenge of replicating the ends of linear chromosomes?

Telomeres are the DNA sequences that are present at the end of chromosomes. The telomeres gets shorten after the DNA replication and are responsible for the ageing process.

The enzyme telomerase is responsible for the replication of telomeres. The telomerase enzyme lengthens the telomeres. This compensate for the the shortening of the chromosomes during each round of DNA replication of the humans.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.