B I O LO GY
,7 Transport in plants ...............................................3
7.1 Structure of transport tissues .........................................3
Structures of stems, root and leaves ..............................5
The transport needs of plants ......................................10
Two systems: xylem and phloem ..................................11
7.2 Transport mechanisms ................................................11
Transport of water .....................................................12
Transport of mineral ions ............................................18
Translocation .............................................................24
Differences between sieve tubes and xylem vessels ......29
8 Transport in mammals........................................31
8.1 The circulatory system ................................................31
The mammalian cardiovascular system ........................31
Blood vessels .............................................................32
Blood plasma and tissue fluid .....................................36
Lymph .......................................................................37
Blood ........................................................................39
Haemoglobin ............................................................41
Problems with oxygen transport..................................45
8.2 The heart ..................................................................47
The cardiac cycle .......................................................49
Control of heart beat .................................................51
, 7 TRANSPORT IN
PLANTS
Flowering plants do not have compact bodies like those of animals. Leaves
root systems spread out to obtain the light energy, water, mineral ions and
that plants gain from their environment to make organic molecules, such as
amino acids. Transport systems in plants move substances from where they
or produced to where they are stored or used. Plants do not have systems f
oxygen and carbon dioxide; instead these gases diffuse through air spaces
roots and leaves.
Candidates will be expected to use the knowledge gained in this section to
in familiar and unfamiliar contexts.
7. 1 S T R U C T U R E O F T R A N S
TISSUES
Plants have two transport tissues: xylem and phloem.
LEARNING OUTCOMES
C ANDIDATES SHOULD BE ABLE TO:
A. draw and label from prepared slides plan diagrams of transverse sectio
roots and leaves of herbaceous dicotyledonous plants using an eyepiec
show tissues in correct proportions (see 1.1c)
1. Biological drawing
- You need the following equipment: