Floral Careers Plant Propagation

Light & Photosynthesis

The Electromagnetic Spectrum

Colors of Light that Plants Use

• Plants absorb red light.• Plants absorb blue light.• Plants don’t absorb green light, they

reflect green light.

Sources of Light

• Sun• Artificial Lights

• Incandescent bulbs• Fluorescent bulbs• Specialized lights for plant growth

HID Lights in the Kirkwood Greenhouse

Where in Plants is Light Being Absorbed?

• Leaves.• Sometimes by the stems.• Specifically light is absorbed by a

chemical compound called chlorophyll.

Chlorophyll

• A green-colored chemical pigment found in the chloroplasts of plant cells.

Leaf Cross-sectional View Showing Plant Cells with Chloroplasts

Does This Plant Have Chlorophyll?

YES!

• Chlorophyll is still present in the leaves.

• It’s presence is masked by the more dominant red and purple pigments.

Autotrophs

• Living organisms capable of manufacturing their own food.

• Plants are autotrophs.

Photosynthesis

• Inputs:• Light• Water• Carbon dioxide• Chlorophyll

Photosynthesis

• Outputs• Oxygen• Sugar (glucose) = Food • See, plants really are autotrophs!

Paul’s Circle of Life

The End