Lesson 13
February 4th, 2011
ORGAN SYSTEMS IN PLANTS
Organs Working Together
 Organs that function together form organ
systems.
 Each organ system consists of a group of
organs that work together to carry out
specific duties.
Plant Organ Systems
 A plant has two organ systems: a
shoot system and a root system.
 The shoot system is everything that is
above ground: the stem, leaves, buds,
flowers, and fruits.
 The root system is everything
underground, as well as aerial roots.
The Shoot System
 The functions of the shoot system include
 Photosynthesis,
 Reproduction,
 Storage,
 Transport,
 Hormone production.
The Root System
Two primary root system types:
 Taproot system - Single primary root
dominates over branch roots ( usually found
in Gymnosperms and most Dicotyledons)
The Root System
Two primary root system types:
 Fibrous root system – A network of fine
roots with no central dominant root. Fibrous
root systems don't go as deep as taproots,
but they spread laterally
Plant Organ Systems
 Both systems need to
work together in the
movement of water in
the plant
 Water enters the root
hairs and travels to
the xylem. Water is
moved against gravity
by transpiration
Plant Organ Systems
 Transpiration is the evaporation of water
through the stomata in the leaves.
 As each water molecule evaporates, it creates
a transpiration pull on the adjacent water
molecules, which pulls the water up the
xylem to the leaves. Once the water reaches
the leaf, the transpiration pull is enough to
move the water from the xylem into the
ground tissue.
Plant Organ Systems
http://www.youtube.com/watch
?v=mc9gUm1mMzc&NR=1
Plant Organ Systems
The organs of a plant also work together to
ensure that the plant survives changes in the
environment.
 Specialized cells record changes in the
exposure to light. When the length of
daylight increases, chemical messages are
delivered to tissues to stimulate the
production of a flower.
 In times of drought and excessive heat, a
plant may decrease its production of leaves
Questions – hand in for
homework
1. What are the two organ systems in a plant?
2. What are some of the main functions of the
shoot system in a plant?
3. What are the similarities and differences
between the two types of root systems?
4. Explain how a plant is able to get water to
the leaves.