Translocation and phloem tissue Flashcards
Translocation is…
the transport of soluble organic substances within a plant.
Assimilates are…
substances which the plant has made itself.
Assimilates are transported in…
sieve elements found in phloem tissue.
Sieve tubes make up…
the phloem. They are tube-like structures, made of living cells.
A sieve tube is made of many…
elongated sieve elements, joined end to end vertically to form a continuous tube.
Sieve element is…
a living cell. The amount of cytoplasm compared to other plant cell is very low and there is no nucleus and no ribosomes.
Sieve plate is formed where…
the end walls of two sieve elements meet. They are made of the walls of both elements, perforated by large pores.
Companion cells have a large number of…
mitochondria and ribosomes as they are metabolically very active.
The companion cells are closely associated…
with the neighbouring sieve element.
Numerous plasmodesmata pass through the cell walls of…
companion cell and the sieve element, making direct contact between the cytoplasm of one and another.
Phloem sap is…
the liquid inside phloem sieve tubes.
The contents of sieve tubes are under…
high pressure.
When a sieve tube is cut…
the release of pressure inside the tube causes a surge of its contents towards the cut.
When the contents of the sieve tube come up…
against a sieve plate, they block it.
Callose is…
a carbohydrate used to seal the sieve plate and prevent the escape of contents.
