XYLEM AND PHLOEM Flashcards
What does the xylem transport?
Water and mineral ions to the leaves
what does the phloem transport?
Sucrose and amino acids, to growing and storage parts of the plant
Why do plants need sucrose and amino acid?
energy, building proteins
which tissue is made up from dead cells
Xylem
What tissue has a cytoplasm?
Phloem
What tissue contain lignin?
Xylem
What is the xylem made up of?
THICC cell walls made up of lignin
what tissue flows both ways?why?
The phloem flows up and down, because the whole plant also needs sucrose for energy.
describe 1 structure of the phloem?(stucture of cells)
The cells are joined end to end and contain holes in the end of cell walls (called sieve plates)
What are sieve plates?
A sieve plate is a wall with holes in it
Name two sub cellular structures in the phloem
Cell walls made up of cellulose, and a cytoplasm
Describe two other structures of the phloem?L
- )Each cell is formed with cellulose with holes called sieve plates
- )the living cytoplasm extends through the holes of the sieve plates,
- )linking each cell with the next,
- )forming a long SIEVE TUBE
What is the function of the sieve tubes?
transports products of photosynthesis,from the leaves to other part of the plant,
-)allows easy flow of substances from one cell to the next
Where might sugars of the plant be transported?
to the roots and converted into starch for storage
what is translocation?
The transport of sucrose and amino acids in phloem
What is the main difference of the phloem and xylem?
Xylem has dead tissues at maturity, but NO cell contents.
Phloem is the living tissue, but no nucleus
Does the phloem sieve plates have a nucleus?how?
no, they are controlled by COMPANION CELLS, that are next to the sieve plates
What is a source?
source (where it’s made)
What is a sink?
source (where it’s made) to sink (where it’s stored or used)
During winter what might the phloem tubes do?why?
During winter, when many plants have NO leaves, the phloem tubes may transport DISSOLVED sucrose and amino acids FROM the roots to other parts of the plant so that respiration can
continue
During a growth period (e.g during the spring) what does the phloem do?source?sinks?
the storage organs (eg roots) would be the source and the many growing areas of the plant would be the sinks
What happens in the summer?
the leaves become the source, loads of photosynthesis happening
which way does xylem transport water and minerals?
roots to leaves
What is deposited in the xylem that causes it to die?
A substance called LIGNIN is deposited in the cell walls, causing the xylem cells to die
what is lignification?
Lignin being BUILT into the cell walls (of the xylem)
Once fully lignified what happens to the xylem?
They DIE and become hollow dead tubes
-) join end-to-end to form a CONTINUOUS TUBEE for water and mineral ions TO TRAVEL from the roots
What does lignin do for the xylem?
STRENGTHENS the plant, to help it withstand the pressure of water movement
How is a continuous column of water created in the plant?
Water molecules are attracted to each other by hydrogen bonding
