America's Source for High School Sports and the leading volleyball organization team up to honor the nation's best. (Week of 9/2-10/4).
Phloem Structure Phloem is composed of several cell types including sclerenchyma, parenchyma, sieve elements and companion cells. The sieve element and companion cell are found closely associated with each other in what is referred to as the sieve element/companion cell complex.
only leaves have phloem and only roots have xylem. b. the cells of roots have cell walls that are lacking in leaf cells. c. a waxy cuticle covers leaves but is absent in roots. d. vascular tissue is found in roots but it is absent from leaves.hich functional plant cells lack a nucleus? a. xylem only b. sieve tube cells only c. companion cells only d. both companion and parenchyma cells e. both xylem and sieve tube cells 4. The fiber cells of plants are a type of a. parenchyma. d. meristematic cell. b. sclerenchyma. e. phloem cell. c. collenchyma.