sieve tube elements are the cells of phloem which allow transportation of photosynthates through phloem...
how sieve tube elements form sieve tubes:
sieve tube elements are connected end to end and form a long chain which is called sieve tube,,,,
sieve tube elements are connected with the help of a side chain with the help of peptide bond...also one element has tapering end which easily overlaps with other end of next element to form sieve tube,,,,
