Plant Adaptations

What does a plant need to survive? Water - H2O Sunlight - solar radiation A way to harvest the sun’s energy - pigments Carbon Dioxide - CO2

Adaptations to water conditions. Waxy cuticle Needles Cactus spines Leaf shape – drip edges Die back in drought Guard cells close stomates

Adaptations to Light More pigments to catch different wavelengths Low light conditions need to collect as many wavelengths as possible Red wavelengths absorbed first by water, blue wavelengths absorbed least. What color phytoplankton do you expect at deepest levels for photosynthesis (about 50 meters deep) Do you think spinach is a high or low light adapted plant? Why?

Pigments Phycobilin – red pigment absorbs at blue wavelengths so deep water Anthocyanin – red-brown pigment can act a sunscreen Carotene – orange pigment (transfer electrons) Chlorophyll a – bright green Chlorophyll b – dull olive green Xanthophyll – yellow (transfer electrons)

More Adaptations to Light Phototropism Broad thin leaf Photosynthetic cells near top surface Cytoplasmic streaming MwMs&safety_mode=true&persist_safety_m ode=1 MwMs&safety_mode=true&persist_safety_m ode=1 Structure of the chloroplast stacked thylakoid membranes

Adaptations to Carbon Dioxide Stomate opening allows air in Spongy tissue has air spaces to allow gases to travel throughout the leaf

Inside the leaf of a plant… xylem Phloem Epidermis Palisade mesophyll Cuticle Stoma Spongy mesophyll Guard cells