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!