Download 23-3 Stems

23–3 Stems
I) ______________ Structure and Function
Stems have ________________ important functions:
•
they produce ____________________, branches and _________________
•
they hold leaves up to the ___________________
•
they transport substances between ______________ and _________________
A) Stems make up an essential part of the water and __________________ transport
systems of the plant.
B) Xylem and __________________ form continuous tubes from the roots through
the stems to the ___________________.
1) This allows water and ___________________ to be carried throughout the
plant.
C) Stems are surrounded by a layer of ______________
cells that have thick cell walls and a _____________
protective coating.
1) Leaves attach to the stem at structures called
_________________.
(a) The regions of stem between the nodes are
______________________.
(b) Small ____________ are found where leaves
attach to __________________.
•
Buds contain _____________________
tissue that can produce new stems and
leaves.
D) In larger plants, stems develop ________________ tissue that helps support
leaves and _____________________.
II) Monocot and _________________ Stems
A) The arrangement of __________________ in a stem differs among
_______________ plants.
PDF created with pdfFactory trial version www.pdffactory.com
1) In _________________, vascular bundles are _________________
throughout the stem. In ________________ and most gymnosperms, vascular
bundles are arranged in a ____________________ pattern.
B) ___________________ Stems
1) Monocot stems have a distinct
_________________, which encloses vascular
bundles.
2) Each ___________________ bundle contains
______________ and phloem tissue.
3) Vascular bundles are _________________
throughout the __________________ tissue.
4) Ground tissue consists mainly of
______________________ cells.
C) _________________ Stems
1) Dicot stems have vascular bundles arranged in a
________________ pattern.
2) The ____________________ cells inside the
vascular tissue are known as ___________.
3) The parenchyma cells outside of the vascular
tissue form the _____________ of the stem.
III) _____________________ Growth of Stems
A) All seed plants undergo ________________ growth, which is an increase in
_________________.
B) For the entire life of the plant, new _____________ are produced at the tips of
roots and shoots.
C) Primary growth of stems is produced by cell divisions in the apical
_________________. It takes place in all seed plants.
IV) ____________________ Growth of Stems
A) The method of growth in which stems increase in ________________ is called
secondary growth.
PDF created with pdfFactory trial version www.pdffactory.com
1) In ____________________ and _______________, secondary growth takes
place in the __________________ cambium and _______________ cambium.
(a) Vascular cambium produces vascular ________________ and increases
the ___________________ of stems over time.
(b) Cork cambium produces the outer __________________ of stems.
•
The addition of new tissue in these cambium layers increases the
thickness of the stem.
B) Formation of the Vascular _______________________
1) Once ___________________ growth begins, the vascular cambium appears as
a thin layer between the ______________ and ________________ of each
vascular bundle.
2) The vascular cambium divides to produce _____________ cells toward the
_______________ of the stem and phloem cells toward the ______________.
3) These different tissues form the ____________ and wood of a mature stem.
C) Formation of _______________
1) Wood is actually layers of ______________.
These cells build up year after year.
2) As woody stems grow ________________,
older xylem cells near the center of the stem
no longer conduct ______________.
(a) This is called __________________.
Heartwood supports the tree.
(b) Heartwood is __________________ by
sapwood.
(c) ___________________ is active in water and mineral transport.
D) Formation of Bark
1) On most trees, bark includes all of the tissues _________________ the
vascular cambium — phloem, the ____________ cambium and cork.
2) The ___________________ cambium produces new xylem and phloem,
which increase the width of the stem.
3) The phloem transports _______________ produced by __________________.
PDF created with pdfFactory trial version www.pdffactory.com
4) The cork cambium produces a protective layer of ____________________.
5) The cork contains old, nonfunctioning __________________ that protects the
tree.
PDF created with pdfFactory trial version www.pdffactory.com