A problem known as the end-replication problem (telomere problem) exists in eukaryotic chromosomes wherein the chromosomes shorten with each round of DNA replication. Select the statements that best explain why the end-replication problem exists in eukaryotic chromosomes (select all statements that apply)
1) The RNA primer is removed in a 3' to 5' direction
2) DNA polymerase requires a primer for DNA synthesis
3) DNA ligase links the 5' OH group of one fragment to the 3' phosphate group of an adjacent fragment
4) The lagging strand is synthesized from the 3' end to the 5' end
5) DNA polymerase synthesizes DNA from the phosphate end to the hydroxyl end

Explanation:

DNA replication occurs in S phase of cell cycle, is the process of DNA duplication in which one molecule of DNA is copied into two molecules. DNA is replicated by DNA polymerase enzyme which requires primer for initiation of replication. In leading strand, only one primer is required at the time of initiation, but for lagging strand, lots of primers are required, one at each okazaki fragment.

Telomere become short at each cell division because DNA polymerase requires a primer for DNA synthesis  and DNA polymerase synthesizes DNA from the phosphate end to the hydroxyl end both the conditions are not filled at the telomeres.

Explanation:

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.