During the growth of a plant, its leaves act as the source of food as they carry out photosynthesis. The phloem conducts the food from the source to the sink (the part of the plant requiring or storing food). During spring, this process is reversed as the food stored in the sink is mobilised toward the growing buds of the plant, through the phloem. Thus, the movement of food in the phloem is bidirectional (i.e., upward and downward).
The transport of water in the xylem takes place only from the roots to the leaves. Therefore, the movement of water and nutrients in the xylem is unidirectional.
Which of the following is not correct?
(a) Robert Brown discovered the cell.
(b) Schleiden and Schwann formulated the cell theory.
(c) Virchow explained that cells are formed from pre-existing cells.
(d) A unicellular organism carries out its life activities within a single cell.
Name two cell-organelles that are double membrane bound. What are the characteristics of these two organelles? State their functions and draw labelled diagrams of both.
Mention the ploidy of the following:
protonemal cell of a moss;
primary endosperm nucleus in dicot,
leaf cell of a moss;
prothallus cell of a fern;
gemma cell in Marchantia;
meristem cell of monocot,
ovum of a liverwort, and
zygote of a fern.
Useless
could you explain the food transportation from phloem to xylem?
But during the transport of food, water is also moved towards the srorage bodies which can be root in Plants like beetroot.