leaves s7-3-1 look! vascular tissue!. 1 main function of a leaf make food it uses the process...
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1 main function of a leaf
Make food It uses the process photosynthesis to
make food for the plant (more on this later!)
2 types of leaves
Simple—blade in one piece
Ex. maple, oak, apple trees Compound—blade
is divided into many leaf-like parts
Ex. marigold, sensitive plant
Photosynthesis
Food is synthesized (made) using sun’s energy
Sun’s energy is captured by chlorophyll (green pigment in the leaf)
Chemical reactions take place—sugar (AKA glucose AKA C6H12O6)
6H2O + 6CO2 ----------> C6H12O6+ 6O2
C6H12O6
**AKA = Also Known As
Add sunlight
Parts of a leaf
Mesophyll: inner part of leaf
Veins: Phloem & xylem
Cuticle: waxy covering, prevents excess water loss
Epidermis: outer covering
Palisade mesophyll: most chloroplasts located here
Spongy mesophyll: gases (CO2 & O2) are exchanged here
Stoma: opening for CO2 to come in & O2 to go outGuard cells: Surround stoma, regulate its opening & closing
Enlarged view:
**I apologize for this blurriness of this picture!It is as if the leaf is cut in half and you are looking at a side view!
Transpiration Water is evaporated
through the leaves by the sun
Each time a water droplet is “picked up,” it pulls the next droplet through
This is how the water gets from the roots to the leaves
Red arrows show the path of the water
Specialized leaves #1
Tendrils—Thin leaves that reach out and “lasso” objects to help plant extend itself
Ex. peas, pumpkins
Spines—Thin, pointy leaves; help to reduce water loss
Ex. Cacti
Specialized leaves #2
Reproduction— “babies” drop from the grown leaf
Ex. Spider plant Kalanchoe
• “Fake petals”—Some leaves are brightly colored and look like petals (to attract pollinators)• Ex. Poinsettias
Specialized leaves #3 Carnivorous plants—some leaves catch
insects to eat sundew
insects get stuck on sticky drops on leaves
Pitcher plantInsects land on leaf and slide down
into digestive juice Venus flytrapSnap shut when insect lands on leaf
We EAT the leaves of many plants!
Specialized leaves #4 FOOD!
Cabbage
Herbs, such as parsley
and basil
Spinach
Lettuce
Bulbs: Onion and garlic
Cloves
Questions: Please answer of separate piece of paper
1. List the one main function of a leaf.2. What category of leaf is shown here:3. What 2 substances react with each other during
photosynthesis?4. What 2 substances are produced through
photosynthesis?5. Can a plant make food in the dark? Explain.6. What part of the leaf captures the sun’s energy? In
which section of the leaf are these organelles located?7. What is the job of the cuticle?8. In which direction does transpiration move water?9. Name 3 specialized functions of leaves (besides food).10. List your 3 favorite leaf foods.
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