Final answer:
After telomerase is removed, primase and DNA polymerase synthesize the complementary DNA strand, but cannot complete the very end, leading to telomere shortening in adult somatic cells.
Step-by-step explanation:
During telomere synthesis, the telomerase enzyme plays a pivotal role. When telomerase is removed, primase and DNA polymerase synthesize the complementary strand by creating a primer and adding DNA nucleotides, respectively.
However, at the very end of the lagging strand synthesis, post telomerase activity, there arises an issue: the RNA primer used for the last Okazaki fragment cannot be replaced with DNA since there is no upstream DNA for a DNA polymerase to continue adding nucleotides. This ultimately leads to progressive shortening of the telomere after each cell division in adult somatic cells, which do not typically express telomerase. In contrast, germ cells and adult stem cells maintain their telomere length due to active telomerase.