Structural adaptations of phloem

The cells that make up the phloem are adapted to their function. Each sieve tube has a perforated end so its cytoplasm connects one cell to the next Companion cells. transport of substances in the phloem requires energy. One or more companion cells attached to each sieve tube provide this energy.

Explanation:

a chair, a bed, and a toothbrush

explanation:

i was told this before by a teacher, so yeah

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).