basic plant physiology

Basic Plant Physiology

Ag. I

By: Jessica George

Basic Parts of a Flowering Plant

• Roots

• Stems

• Leaves

• Flower

Functions of Roots 1. Anchor plant

2. Absorb water and minerals

3. Translocate water and minerals

to stem

4. Store food

Types of Roots

A. Tap Root– Continuation of the primary root– Ideal for anchorage– Penetration is greater for water– Storage area for food made by photosynthesis

Types of Roots

B. Fibrous Roots– Many finely branched secondary roots– Shallow roots cover a large area

• More effective absorption

of water and minerals

• Roots hold the soil to

prevent erosion

Types of RootsC. Aerial roots

• Short roots that grow horizontally from the stems

• Roots that fasten the

plant to a support

– Absorptive air roots

Types of Roots

D. Adventitious Roots– Develop in places other than nodes– Can form on cuttings

and rhizomes

Root Hairs

• Tiny one celled hair like extensions of the epidermal cells located near the tips of the roots wherevascular tissues have formed.– Increase surface area– Absorb water and minerals from

soil

Functions of Stems

1. Translocate water, minerals and food to the leaves

2. Support the leaves and display them to light

3. Store Food

Specialized Stems

A. Corm (gladiolus, crocus)– underground– Solid, fleshy, scale covered

Specialized Stems

B. Bulb (tulips, lillies, onions)– Layers of fleshy scales that overlap each other– Underground stem

Specialized Stems

C. Tuber (potato, caladium)– Food storage area– Short, thick underground stem

Specialized Stems

D. Crown (African Violets, fern)– Closely grouped stems or plantlets– Just above ground or just below

Specialized Stems

E. Spurs (pear and apple trees)– Short sems found on woody plant limbs

adapted for increased production of fruits

Specialized Stems

F. Rhizomes (iris, lily of the valley)– Underground stems that produce roots on the

lower surface and extend leaves and flower shoots above the ground

Specialized Stems

G. Stolon (Strawberry, airplane plant)– Stem that grows horizontally above the soil

surface

Functions of Leaves

1. Make food through photosynthesis

2. Provide site of gas exchange

3. Store food

Parts of a Leaf

Functions of Flowers

1. Contain organs for specialized sexual production

2. Produce seeds and fruit

Parts of the Flower

• Sepals– Outer covering of the flower bud– Protects the stamens and pistills when flower is

in bud stage

Parts of the Flower

• Petals– Brightly colored– Protects stamen and pistills– Attracts pollinating insects

Parts of the Flower

• Stamens– Male Reproductive part– Anther-produces pollen– Filament-supports the anther

Parts of the Flower

• Pistil– Female reproductive part– Ovary

• Enlarged portion at base of pistill

• Produces ovules which develop into seeds

– Stigma• Holds the pollen grains

Parts of the Flower

• Style– Connects the stigma with ovary– Supports the stigma so that it can be pollinated

Complete and Incomplete Flowers

• Complete: have all four main parts– Sepals– Petals– Stamens– Pistils