Why are there holes in the ends of phloem tubes?

There are holes in the end of the phloem tubes because Phloem consists of sieve tube cells and companion cells for conduction of food These sieve elements are placed end to end . At the the junction of two sieve elements there is a plate called sieve plates having circular pores.

the animal that would be cutest if scaled down to the size of a cat? elephant

the three components of a nucleotide are the nitrogenous base, the phosphate group and the five-carbon sugar.