21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
The student is expected to:
4B investigate and explain cellular
processes, including homeostasis, energy
conversions, transport of molecules, and
synthesis of new molecules;
5B examine specialized cells, including
roots, stems, and leaves of plants...;
10B describe the interactions that occur
among systems that perform the functions
of transport, reproduction, and response in
plants;
10C analyze the levels of organization in
biological systems and relate the levels to
each other and to the whole system
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
KEY CONCEPT
Roots and stems form the support system of vascular
plants.
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
!   Roots anchor plants and absorb mineral nutrients from
soil.
•  Roots provide many
functions.
–  support the plant
–  absorb, transport,
and store nutrients
–  root hairs help
absorption
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
•  There are several parts of a root.
–  root cap covers the tip
root cap
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
•  There are several parts of a root.
–  root cap covers the tip
–  apical meristem is an area
of growth
apical meristem
21.3 Roots and Stems
•  There are several parts of a root.
–  root cap covers the tip
–  apical meristem is an area
of growth
–  vascular cylinder contains
xylem and phloem
vascular cylinder
TEKS 4B, 5B, 10B, 10C
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
•  There are two main types of roots.
–  Fibrous root systems have fine branches.
–  Taproot systems have one main root.
Fibrous root
Taproot
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
!   Stems support plants, transport materials, and provide
storage.
•  Stems have many functions.
–  support leaves and flowers
–  house most of the vascular system
–  store water
Baobab trees
Cactus
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
!   Stems support plants, transport materials, and provide
storage.
•  Stems have many functions.
–  support leaves and flowers
–  house most of the vascular system
–  store water
–  grow underground for storage
Ginger rhizomes
Potato tubers
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
!   Stems support plants, transport materials, and provide
storage.
•  Stems have many functions.
–  support leaves and flowers
–  house most of the vascular system
–  store water
–  grow underground for storage
–  form new plants
Strawberry
stolons
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
•  Some stems are herbaceous and conduct photosynthesis.
21.3 Roots and Stems
•  Some stems can be woody,
and form protective bark.
TEKS 4B, 5B, 10B, 10C
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
•  Primary growth increases a plant’s length.
•  Secondary growth increases a plant’s width.
21.3 Roots and Stems
TEKS 4B, 5B, 10B, 10C
•  Tree rings help determine the age of a tree.
bark
bands
heartwood
one year
of growth
sapwood