Leaf Anatomy & Morphology

Bell Ringer:

Why do you think that some leaves are broad and flat and others are shaped very different?

How could you connect the shape of leaves to the cellular processes that are essential for plants to live?

Leaf Anatomy&

Morphology

What are the main parts of a leaf?• Leaves are the primary food producing organs

of the plant• They are designed to collect light and use that

energy to produce food

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What are the main parts of a leaf?

• The main sun collecting structure is the leaf blade

• The blade has many layers, which help the plant move and store photosynthesis materials and by-products.




• The blade is supported by the petiole.

• The petiole is similar to the stem and can transport water and sugar.




• Many leaves are organized with one main vein running down the middle of the blade.

• This vein is called the midrib.




• The veins, the petiole, and the midrib help position the blade to face the light source.



What are some of the major types of leaves?

• Some leaves are adapted to hot, dry climates by storing water or being smaller.

• Some leaves have very large blades to collect the maximum light in a shady location.


• A leaf which has only one blade on its petiole is called a simple leaf. (Most plants have simple leaves.)




• A leaf with multiple blades is called a compound leaf.



What are some vein patterns found in leaves?

• Monocots: parallel veins - none of the veins cross each other



What are some vein patterns found in leaves?

• Dicots: netted veins - veins which connect and branch from each other



How is a leaf organized?• A leaf is organized to collect sunlight and turn it,

through photosynthesis, into food.• The leaf blade has many layers of tissue to allow this to

happen.

How is a leaf organized?• The cuticle prevents water from escaping.• The epidermis is there for protection and is found on

both the top and bottom surface of the leaf.



How is a leaf organized?• Beneath the upper epidermis are the palisade

mesophyll cells.• These cells are responsible for most of the

photosynthesis in the leaf.



How is a leaf organized?• The spongy mesophyll forms air spaces which hold

products of photosynthesis.• The lower epidermis has holes called stomata that

open and close to allow for gas exchange.



Exit Slip question:



• Label the indicated parts of the leaf and the leaf cross section.



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Homework

• Write a summary for your Cornell notes from the textbook pages 70-76 and the notes that you added from the power point presentation today.

• Your summary MUST include a claim that you can support using scientific evidence and reasoning from your notes.

Leaf Anatomy & Morphology

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