HOW DO LEAVES HELP A PLANT?
Let's watch this quick video to learn more about photosynthesis. CLICK HERE
Watch this video on Photosynthesis!
- In the leaves of a plant is a substance called chlorophyll. Chlorophyll makes leaves green. It also traps the energy from the sun so the plant can use it.
- When plants take carbon dioxide from the air, they release oxygen. Animals use this oxygen to grow. We release carbon dioxide, which the plants use.
- Plants also need minerals from the soil to grow. Nitrogen helps them grow and make leaves. Phosphorus helps grow strong roots. Potassium helps the plant make fruit and it keeps them healthy.
- Plants need large amounts of nitrogen, phosphorus and potassium. The soil doesn't always have enough of these nutrients. Gardeners use fertilizer to give plants more nutrients. Fertilizers are sort of like vitamins for plants. Some fertilizers are made from chemicals. Others are made from natural things like cow manure. That’s right – poop has lots of nutrients for plants!
- Click here to learn more about plants with Bill Nye the Science Guy!!
This pic shows a leaf cross section with only the layers labeled.
The top & bottom layers are both referred to as an epidermis (outer layer). The upper epidermis (colored purple) & the lower epidermis (colored red) basically are protective layers. They are coated with a waxy surface, the cuticle, which further protects the leaf & prevents excess water loss.
The area sandwiched in the middle of the leaf is referred to as "mesophyll". There are two layers in the mesophyll:
1) the palisade layer - packed tight w/ oval cells
2) the spongy layer - this area contains circular cells that are spread out --- allowing gases to circulate within the leaf
If you've ever looked closely at a leaf you've noticed some pattern of lines running through it.
These lines are veins, or "vascular bundles" (the side of one bundle is colored light green).
Inside the vascular bundle are tubes that transport materials from place to place in the plant.
The xylem (colored blue) transport water & minerals from the roots, through the stem, & into the leaves
(remember ... we need water for photosynthesis).
Phloem (colored orange) are tubes that transport "food" through the plant. This "food" is basically sugary water (sap). The sugars are synthesized (made) during photosynthesis.