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