Download Importance of Plants Notes

IMPORTANCE
OF PLANTS
Importance of Plants
• Oxygen
• Food/feed
• Medicine
– http://www.youtube.com/watch?v=6iEOTB1UjjQ
• Absorb Carbon Dioxide
• Decoration (Aesthetic)
PLANT LIFE
CYCLES
Plant Life Cycle
• Annual
– Goes from seed to producing seed in one growing season
– Ex. Corn, beans
Summer Annuals
• Summer annuals germinate in the spring.
Summer annuals produce leaves, flowers, and
seed before dying during the summer or fall.
– Many crops and garden plants are annuals.
– Corn, soybeans, rice, wheat, potatoes, and tomatoes
– Petunias, impatiens, marigolds, and zinnias
– Ragweed, pigweed, lambsquarter, crabgrass
Photo, courtesy USDA Peggy Greb
Winter Annuals
• The seed of a winter annual germinates in the
fall. The immature plant overwinters as a
compact rosette. Once the plant has received a
sufficient period of cold treatment, it bolts.
Winter Annuals
• Bolting is a process in which the stem of a plant
rapidly elongates at the time of flowering.
– Flowers then develop, seeds are set, and the plant
dies.
– Winter wheat
Plant Life Cycle
• Biennial
–
–
–
–
Goes from seed to producing seed in two growing seasons
1st year – vegetative growth
2nd year – vegetative and flower growth
Ex. Carrot, burdock
Biennials
• Biennials are plants that normally require two
growing seasons to produce flowers and seed
before dying.
– First growing season: biennials grow vegetatively.
– Next: plants go dormant and rest until the Spring
– Winter: receive a required cold treatment
– Growth is resumed in the spring of the 2nd season.
– The plants bolt, flower, produce seed, and die.
– Hollyhock, Sweet William, parsley, beets, and carrots
Plant Life Cycle
• Perennial
– Lives more than two growing seasons
– Ex. Trees, shrubs
Perennials
• A perennial is a plant that has a life cycle of more
than two growing seasons.
– May take perennial plants a few years to many years
to reach reproductive maturity.
– Perennials may be woody like trees
and shrubs or herbaceous.
On the flip chart(s) – create a
Venn-Diagram to compare and
contrast the three types of plant
life cycles
MAJOR PLANT
STRUCTURES
Major Plant Structures
• Flower
– Attracts insects for
pollination
• Fruit
– Seed-carrying structure
Major Plant Structures
• Seeds
– Produces new plants
• Leaves
– Produces food/sugars
Major Plant Structures
• Stem
– Supports the plant
– Transports water,
nutrients and
food/sugar
• Roots
– Anchors plant
– Absorbs water and
nutrients
– Stores food