Video Transcript
After the photosynthesis process,
the transport of phloem sap would be inhibited in the absence of blank. (A) Companion cells, (B) tracheids,
(C) xylem vessels, or (D) cambiums.
Much like humans, plants need a
vascular system to transport vital molecules like sugars and water to all of their
cells. This question asks us about the
transport of phloem sap, which occurs in specific plant vascular tissues called the
phloem.
The phloem is responsible for
transporting solutes like the sugars that are produced in photosynthesis and amino
acids in the form of phloem sap. Generally, phloem sap is
transported from the leaves, where most photosynthesis takes place, both up and down
the stem to all the parts of the plant that require the substances it carries.
The phloem is made up of four main
types of cell. They include sieve tube members,
which are otherwise known as sieve tube elements; companion cells; fibers; and
sclereids. Fibers and sclereids have not been
shown in this diagram, as their main function is to provide structural support to
the phloem. The sieve tube members are stacked
end to end with sieve plates between each cell through which phloem sap can
pass. The companion cells contain many
mitochondria. These mitochondria are essential as
they carry out cellular respiration to release the energy that is needed for the
transport of phloem sap through the phloem.
With this information, we know the
word that would appropriately fill in the blank in the statement and can therefore
answer this question correctly. After the photosynthesis process,
the transport of phloem sap would be inhibited in the absence of (A) companion
cells.
