10.3 Transport in plants (Book 1B, p. 10-22)
What structures are responsible for transport in flowering plants? (Book 1B, p. 10-22)
Ø (1) Vascular bundles (維管組織) are specialized structures for the transport of substances in flowering plants.
Ø The vascular bundles (維管束) are formed by two types of vascular tissues:
n (2) xylem (木質部)
n (3) phloem (韌皮部)
n is responsible for transporting (4) water and (5) minerals.
n mainly consists of (6) xylem vessels (木質導管).
n Structure of xylem vessels:
How is vascular tissue distributed in flowering plants? (Book 1B, p. 10-23)
Ø Xylem and phloem are arranged in large, separate strands called (18) vascular bundles in flowering plants.
Ø Distribution of the vascular bundles in the roots, stems and leaves of dicotyledonous plants is different:
n Vascular bundles are found in the large central
(12) mid rib and the network of small veins.
n Xylem lies at the (13) top of phloem.
n Vascular bundles are separate and usually arranged in a ring at the (14) periphery.
l (15) xylem is located in the inner region
l (16) phloem is in the outer region
n Vascular bundles are located at the (17) centre.
n Phloem is found between xylem.
How are water and minerals transported in flowering plants? (Book 1B, p. 10-25)
1 Water is lost from leaves through (18) transpiration.
Transpiration pull is created.
v The continuous hollow tube-like structure of xylem vessels allows a continuous stream of water to be formed inside them. Water is drawn
up the (19) xylem vessels by transpiration pull as a continuous stream.
(20) Minerals dissolved in water are transported up the plant along with the water.
w Water and minerals in the soil are absorbed into (21) the root.
How are organic nutrients transported in flowering plants? (Book 1B, p. 10-27)
Ø Organic nutrients are transported from the site of production (e.g. leaves) to the parts where they are:
n consumed (e.g. buds芽 and roots) or
n (23) storage organs (e.g. fruits).
Ø The transport of organic nutrients in plants is called (24) translocation (輸導).
Ø Organic nutrients are transported in (25) phloem.