Section 1

 List some plants you know in general ◦ Trees ◦ Flowers ◦ Vegetables ◦ Fruits ◦ Field crops  Wheat  Rice  Corn  There are between 260,000 and 300,000 plant species that have been identified

 Plants range in size ◦ Microscopic to giant trees  Have roots or root-like structures ◦ Hold them into the ground  Adapt to different environments

 Plants are made of cells ◦ Cell membrane, nucleus, and other cellular structures ◦ Have a cell wall that provides structure and support  Animal cells DO NOT have a cell wall  Plants cells contain the green pigment chlorophyll ◦ Makes them green ◦ Needed for photosynthesis ◦ Found in the cellular structure chloroplasts

 Most plant cells have a central vacuole ◦ Regulates water content inside of a cell ◦ Stores pigments that make some flowers red, blue, or purple.

 The first plants probably could only survive in damp areas  Their ancestors were probably green algae that lived in the sea ◦ Today plants and green algae have the same types of chlorophyll and carotenoids in their cells ◦ Carotenoids are red, yellow, or orange pigments that are also used for photosynthesis  Plants and green algae have a common ancestor

 Plants usually decay before they become a fossil this makes tracing the plant history difficult  The oldest plant fossils are 420 myo  Some of the early plants evolved into the plants that exist today

 Cone-bearing plants (pine trees) probably evolved from a group of plants 350 million years ago  Flowering plants did not exist until 120 million years ago

 Advantages to life on land for plants ◦ More sunlight and carbon dioxide – need for photosynthesis

 Cuticle: Waxy, protective layer secreted by cells onto the surface of a plant ◦ Slows water loss  Cellulose: Provide structure and support for the plant  Vessels: Distribute materials throughout the plant

 Cells of some plants secrete other substances into the cellulose to make the cell wall stronger ◦ Oaks and pines could not grow without this substance  For plants on land: ◦ Structures distribute water, nutrients, and food to all plant cells

 To reproduce on land some plants developed water-resistant spores  Other plants produce water-resistant seeds in cones or in flowers which develop into fruit

 The two main plant groups: ◦ Vascular: Have tube-like structures to transport water, nutrients, and other substances throughout the plant ◦ Nonvascular: Do not have tube-like structures for transport. These plants use other methods to transport water, nutrients, and other substances.  Plants are named using the two part naming system binomial nomenclature