Plant Science
All Life Depends on Plants
Why are plants important?
• Plants Clean the air –
by taking in carbon dioxide and producing
oxygen.
• Make surroundings more attractive
• Food
• Medicine
• Clothing
• Housing
How does it all relate?
Plant Classification
1. BINOMIAL NOMENCLATUREThis is what scientist use to name and group plants.
2. How do we group them together?
- grouping plants according to their similarities
A. Physical
B. Life Cycle
3. The groups are (from largest to smallest)
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
Plant Life Cycles
• Life Cycle –
The length of time it takes
a plant to complete life
from germination to death
- Measured in
growing seasons
- Refers to the period of
temperatures are
favorable for plant growth
Life Cycle of Plants
1. Completes its entire life cycle in a single
growing season is called ____________
Annuals
Usually planted in March – June
Dies before the first fall frost
2. Biennial –
Completes its life cycle two growing seasons.
– Grow during first season reproduce 2nd season
How can they do this?
store food in their roots
Life Cycle of Plants
3. Perennial
- Requires 3 or more growing seasons to
complete the life cycle.
They often reproduce often during their life
span.
Examples: Apple trees and pines, roses,
shrubs.
Plant Life Cycle
• Summer Annuals
– Planted in spring,
harvested in fall
• Winter Annuals
– Planted in fall,
harvested in
following summer
Seed Germination & Seed Growth
A.
3 Stages of Growth
& development
1. Seed germination &
seed growth
2. Vegetative growth
3. Reproduction
Seed Germination & Seed Growth
B. What factors do we need to consider before
planting our crops?
1. Soil Temperature
2. Soil Moisture
3. Seed quality (germination %)
4. Date of Planting
5. Type of soil
If we ignore these factors how does it affect our crop?
The Leaf
 Purpose
–
They are the “factories of the
plant”.
2 major parts
The Blade & Petiole,
Blade- is the flatten part
expanded part of a leaf
Petiole – is the cylindrical part
that attaches to the stem
The Leaf
 Center
of the leaf has
many cells called
chloroplast.
 They are responsible for
photosynthesis
 Photosynthesis –
Chemical process that
converts water and co2 to
glucose sugar & O2
It is the most important
process in the world
2 subclasses for seeds
1. Monocot –
has only one seed leaf
when it emerges from the
soil.
• Stored food in endosperm
• Veins are parallel.
• Ex: corn, wheat, oats, rye,
barley (grass plants)
Seed Leaves
2. Dicots Plant that has 2 seed
leaves when it
emerges from the soil.
Leaves with network of
veins
• Vascular bundles form
ring outside of stem
• Examples: alfalfa,
soybeans
What is the Purpose of a Stem on a
Plant?
Vegetative part of the plant that
supports leaves, buds, & other
organs.
Used to help transport food,
water & nutrients in a plant
Inside the stem contains:
Xylem, Phloem, Pith, Epidermis,
cortex, & sometimes the cambium
Vascular Systems

Xylem & Phloem
Xylem –
Tissues that carries water &
minerals from the root hairs
throughout the plant.
Most fluid movement is
upward.
Vascular Systems

Phloem –
Tissue that carries plant
products such as glucose
from production sites to
othe parts of the plant.
 Fluids are usually
moving from leaves to
the roots
Vascular Systems

 Cambium –
The site of all new cell production in the stem.
Creates both Xylem & Phloem
If a plant has no cambium – the plant makes all the cells
it will ever have during its intial growth.
As the plant grows further, these cells just enlarge.