Plant
Structures,
Reproduction,
and Responses
Levels of
Organization
Copy this graphic organizer into your journal
What are the 2 Types of
Plants?
 BRYOPHYTES
 Mosses, liverworts,
hornworts
 NO tissue to
transport water and
nutrients
 NON Vascular
 TRACHEOPHYTES
 Vascular plants
 Have tissue for
transporting water
and nutrients
What is Vascular Tissue?
 Function: to transport water
and nutrients between roots,
stems, and leaves
 2 Types:
 Xylem: transports water
from roots to shoots
 Phloem: transports sugar
from leaves to roots (and the
rest of the plant)
 Like our circulatory system
Stem Cross-Section
What are the organs of the plant?
• Roots
• Stems
• Leaves
What kinds of roots are there?
STRUCTURE:
•Taproot – long, thick
root that is the main
root of the plant
•Fibrous roots – many,
smaller branching roots
What are the functions of
Roots?
 Anchor the plant to the
ground
 Absorb water and
minerals
 Store sugars or starches
What are the functions of the
Stem?
 Growth of the plant,
including production of
leaves, branches, and
flowers
 Support – stems hold
leaves up to the light
 Transport of water and
sugars between the roots
and leaves
What are the functions of
the leaf?
 Photosynthesis – plant cells use sunlight to convert
carbon dioxide and water into sugars
6 CO2 + 6 H2O + light  C6H12O6 + 6 O2
 Transpiration – water is pulled from the roots and
stems of the plant as it evaporates from the surface of
the leaves
 Gas exchange – leaves take in carbon dioxide for
photosynthesis and release oxygen and water vapor
into the air
What are the Parts of a
Leaf?
 blade: the flat part of the leaf that catches sun
 Petiole: the thin stalk that attaches the leaf to the
stem
Important Leaf structures
 Stomata / Stoma
 Pores on the undersides of
leaves
 Control transpiration rate and
allow gas exchange
 Guard cells are specialized cells
that control the opening and
No line
closing of the stomata
Draw and label this in your
journal.
What are some examples of
Modified Leaves?
Tendrils for climbing
Succulent Leaves for water
storage
Spines to reduce
transpiration rate
Bracts to attract pollinators
What is Transpiration?
 Loss of water from a plant
through its leaves.
 The force that pulls water
from the roots up to the
leaves.
What is a Conifer
(Gymnosperm)?
 Plants that produce seeds in cones
 No fruit = “Naked seed”
What are Angiosperms?
 Flowering plants
 Produce seeds inside fruit
What are the 2 types of
Flowering Plants?
 Monocots
 Contain ONE
seed leaf
 Dicots
 Contain TWO
seed leaves
What is a Cotyledon?
The seed leaf (inside the seed)
One cotyledon
(seed leaf)
Two cotyledons
(seed leaves)
What are flowers?
 Modified leaves that are for sexual reproduction
draw and label flower in your
journal
What is the Pistil ?
Female Reproductive Structure
stigma receives the
pollen from the
anther
pollen grows a tube
down through the
style
ovary produces
females gamete and
protects developing
seed
Draw this
in your
journal
What is the Stamen?
Male Reproductive Structure
Draw this
in your
journal
anther produces
pollen
pollen - male
gamete, powder
filament is a stalk
that supports the
anther
What is Pollination?
The transfer of pollen from a stamen to a
pistil
What are some Methods of
Pollination?
 Wind
 Water
 Gravity
 Insects/animals
What is Fertilization?
The union of the
pollen and ovule
1. Pollen lands on
stigma
2. Travels down
style
3. Joins with ovule
4. Ovary becomes
fruit
5. Seeds develop
inside fruit
What are the steps of
fertilization?
1. Pollen lands on
stigma
2. Travels down style
3. Joins with ovule
4. Ovary becomes fruit
5. Seeds develop inside
fruit
Draw this
in your
journal
What is Germination?
 When the baby plant
sprouts from the seed and
begins to grow
What are Tropisms?
 A plants’ growth in a certain direction in
response to a stimuli
What are the types of
tropisms?
 Phototropism - growth towards light
 Geotropism – response to gravity
 Roots toward gravity (+)
 Stems and leaves away from gravity (-)
 Hydrotropism – growth towards water
 Thigmotropism – response to TOUCH!
What are some Plant
Hormones?
 Auxins – controls growth and cell elongation, inhibits
lateral (side) growth, stimulates root growth
 Cytokinins – stimulates cell division, opposite of
auxins
 Gibberellins – stimulates growth and stimulates seed
germination
 Abscisic Acid – slows or stops cell division (growth),
promotes seed dormancy
 Ethylene – stimulates fruits to ripen, causes leaves
to fall in autumn