AP Biology 2006-2007

Plant Anatomy

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Basic plant anatomy 1 root

root tip root hairs

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Roots Roots anchor plant in soil, absorb

minerals & water, & store food fibrous roots (1)

mat of thin roots that spread out monocots

tap roots (2) 1 large vertical root also produces many small lateral,

or branch roots dicots

root hairs (3) increase absorptive

surface area

2

1

3

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Stemshoot (stem) Support plant transport water through

xylem transport nutrients through

phloem a celery stalk soaked in food

coloring will absorb the food coloring, you can see the xylem

Two types of stems: herbacious and woody

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Modified shootsstolons (strawberries) rhizome (ginger)

tuber (potato) bulb (onion)

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Basic plant anatomy 3 root

root tip root hairs

shoot (stem) nodes

internodes buds

terminal or apical buds axillary buds flower buds & flowers

leaves mesophyll tissue veins (vascular bundles)

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Leaves Function of leaves

photosynthesis energy production CHO production

gas exchange (stomata) Transpiration Cuticle: waxy covering of

leaf that prevents water losssimple vs. compound

AP Biologysucculent leaves

Modified leavestendrils (peas) spines (cacti)

colored leaves (poinsetta)

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Flower•Reproductive organ of the plant •Flowers are usually both male and female •The male part of the flower is the STAMEN •The female part of the flower is the PISTIL •See your Flower Book for more detail on flower anatomy

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Parts of the Flower• The receptacle (B) is the part

of the branch on which a flower forms.

• Sepals (C) are leaf like structures that surround and protect the flower before it blooms

• Petals (D) are the colorful part of the flower that attracts insects and even other small animals, such as mice, birds, and bats.

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Parts of the FlowerThe flower has both male and female reproductive parts. • The female reproductive

structures are called carpels the carpels are fused together to form a pistil

The pistil (P) has three parts: 1. stigma (J) at the top is often sticky and is where the pollen attaches.2. Style (K) is the long tube that attaches the stigma to the ovary. 3. The ovules (O), or eggs, are stored in the ovary (L) until they are fertilized.

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Parts of the FlowerThe flower has both male and female reproductive parts. The male reproductive structures are called the stamens.

Each stamen (H) consists of an anther (A), which produces pollen, and a filament (F), which supports the anther.

Pollen produced by the anther is carried by insects or other animals to the pistil of another flower where it may fertilize the eggs.

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Plant ReproductionPlant ReproductionSexual reproduction in plants occurs when the pollen from an anther is transferred to the stigma. Plants can fertilize themselves: called self-fertilization. Self-fertilization occurs when the pollen from an anther fertilizes the eggs on the same flower. Cross-fertilization occurs when the pollen is transferred to the stigma of an entirely different plant.

When the ovules are fertilized, they will develop into seeds. The petals of the flower fall off leaving only the ovary behind, which will develop into a fruit. There are many different kinds of fruits, including apples and oranges and peaches. A fruit is any structure that encloses and protects a seed, so fruits are also "helicopters" and acorns, and bean pods. When you eat a fruit, you are actually eating the ovary of the flower.

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Critical Parts of a Seed

BC The technical word for seed leaf is

cotyledon (A): you can find it on the coloring sheet; it is the first leaf to emerge from a developing seed.

The seed consists of the outside seed coat (B) and a large area called the endosperm (C) which functions as a source of reserve materials and food for the developing embryo. As germination occurs, the endosperm will be broken down and used by the plant.