PLANTSName all the plants you can think of…What do these all have in common?

Chapter 9

• Plants are many-celled organisms

- most plants contain chlorophyll

- at least 260,000 plant species have been identified

- plants are adapted to nearly every environment on earth

- plants are important food sources for people and animals

• Photosynthesis - the process by which green

plants use sunlight to make food from carbon dioxide

and water.

- Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.

PLANT CELLS:

• Plant cells have:

- a cell membrane- a nucleus and other organelles- a cell wall- chlorophyll – the green pigment used in photosynthesis- a central vacuole which

regulates the water content of the cell

• Some plants also contain carotenoids - Carotenoids are red, yellow or orange pigments that are also used in photosynthesis

• PARTS:

- A cuticle is a waxy protective layer that covers the stems, leaves and flowers of many plants

- The cuticle helps prevent water loss in the plant

• Cellulose is a chemical compound made out of sugar

- cellulose forms tangled fibers in cell walls and provides structure and support

• Plants can be categorized as vascular or nonvascular

• Vascular plants have tubelike structures that carry water and nutrients throughout the plant

• Nonvascular plants do not have the tubelike structures

• Nonvascular plants use other ways to move water and nutrients

• Nonvascular plants have rhizoids instead of roots. • Rhizoids are structures that anchor the plants

where they grow

• Most nonvascular plants are classified as mosses

• Botany is the science of studying plants.

• In the late 1700s, Swedish botanist Carolus Linnaeus developed a system of classifying living things, using many different characteristics

PARTS OF A PLANT

Leaf – the organ of a plant where photosynthesis takes place

• Stem – support the branches, leaves, and reproductive structures

Roots – act as anchors for a growing plant, holding it in place.

- Water and substances enter a plant through its roots.

Flower – the part of certain plants that develop into fruit

- Flowering plants are called agiosperms

• Gymnosperms are vascular plants that produce seeds that are NOT protected by fruit.

• Gymnosperms have no flowers

• These plants include conifers, such as pine trees,fir trees, and spruce – all are commonevergreen trees

• In a seed plant, there are three tissues which make up the vascular system:

- xylem - conducts water and dissolved nutrients upward from the root and also helps to form the stem

- phloem - conducts sugars and other metabolic products downward from the leaves.

- cambium - a thin layer between the xylem and phloem of most vascular plants that gives rise to new cells and is responsible for secondary growth.

• In a seed plant, some spores develop into pollen

• A pollen grain is a small structure produced by the male seed plant

• The transfer of pollen grains to reproduce is called pollination

• Pollen can be transferred by gravity, wind, water, animals or insects

*FLOWERS* - Flowers have four main parts: petals, sepals,

stamen and pistils

• Petals are the colorful parts

• Sepals are the leaflike parts outside the petals. They form the outside of the flower bud

• Stamen is the male reproductive part; pollen is produced in the stamen

• Pistil is the female reproductive organ; the ovary is the base of the pistil where ovules are found–ovules produce eggs, or reproductive cells