Plant People and Seed Plants. Plants as food How many different plants do we eat for food? Fruits...
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Transcript of Plant People and Seed Plants. Plants as food How many different plants do we eat for food? Fruits...
Plant People and Seed Plants
Plants as food
• How many different plants do we eat for food?
• Fruits – the vegetative (reproductive) part of a plant- all fruits contain seeds
• Vegetable- any other part of the plant- leaf, stem, root
Root Crops
• Rich in calories, easy to grow• Potatoes, beets, radishes, carrots, cassava• Grow underground
Legumes
• Members of the pea family• Protein-rich seeds in pods• Beans, peas, peanuts, soybeans, alfalfa• Relationships with nitrogen-fixing bacteria
that can put nitrogen back into the soil- farmers rotate crops from corn to soybeans
Cereals• Grasses that produce grains (dry, edible, fruit)• Each grain is actually a fruit that develops from a
single flower.• Each corn kernel is a single, fruit• Rich in carbohydrates• More than 70% of all cultivated ground is used for
cereals• Corn, wheat, rice= ½ human calories
Fruits and seeds
• Ovary of fertilized flower will develop into a fruit
• Fruits contain seeds– Seeds with one half- monocots– Seeds with two halves- dicots
Nonfood uses
• Rubber, latex- from rubber tree• Wood-lumber, heating, furniture…• Medicines- aspirin from willow trees– Digitalis- foxglove plant for heart disorders– Cancer treatments from periwinkle– Caffeine – Drugs
Nonfood uses
• Fibers– Paper– Cotton– Flax– Hemp
Seed-Bearing Plants• Gymnosperms- nonflowering– 4 divisions• Cycads• Ginkgos• Conifers• Gnetophytes
• Angiosperms –flowering– 2 subdivisions• Dicots• monocots
Conifers- Coniferophyta
• Pine trees• Produce true cones• Male cones are small, clustered and fleshy• Female cones are large and become woody• Leaves are needle-like
Conifers
• Leaves fall off all year long, but are continuously replaced- called evergreens
• During pollination- males release clouds of pollen that is airborne to the female cones
• Female cones are fertilized 1 year after pollination• Germination may take another year
Conifers
• Sporopohyte is the dominant generation• May grow for many years• Some are found that were growing during the
age of pharoahs
Pine Cones
Angiosperms- flowering plants
• Last group to evolve• Largest group of plants• Seeds enclosed in fruits that grow from
flowers• Flowers are used to attract pollinators• Seeds and fruits are highly valuable
Angiosperms
• By this point we have the following major advntages– Cuticle- nonvascular plants– Vascular tissues- vascular seedless– Seeds- gymnosperms– Flowers- angiosperms
• Angiosperms are at the top of the plant evolutionary tree
Angiosperm transport
• Roots- absorb nutrients and water and transport them up the plant
• Stems- support plant and transport substances up and down the plant
• Leaves- main photosynthetic organ, draws water up the plant from the roots
Flowers
• Highly specialized reproductive structures• Stamen- male part- anther + filament- produces
pollen• Pistil-female part –stigma+style+ovary+ovule-
produces eggs• Pollination occurs when pollen is delivered to the egg
Flowers
Next chapter
• Reproduction– Asexual– Sexual– Flowers– Cones
• Easy chapter!