PARTS OF THE PLANTS

Plant Parts and Functions

What Do Different Plant Parts Do?

Plant parts do different things for the plant.

Roots

Roots act like straws absorbing water and minerals from the soil. Tiny root hairs stick out of the root, helping in the absorption. Roots help to anchor the plant in the soil so it does not fall over. Roots also store extra food for future use.

2 Types of Root Systems

• Taproot System  Primary root grows down from the stem with some small secondary roots forming example: Carrots and Turnips 

• Fibrous System Small lateral roots that spread out just below the soil’s surface example:Corn and Beans 

  

Stems

Stems do many things. They support the plant. They act like the plant's plumbing system, conducting water and nutrients from the roots and food in the form of glucose from the leaves to other plant parts. Stems can be herbaceous like the bendable stem of a daisy or woody like the trunk of an oak tree.

Parts of the Stem

žNode

Areas where side branches and leaves develop from

žInternodes

Area between nodes

žLenticels

Small holes located in the stem (breathing pores)

Functions of the Stem 

     Transports water and nutrients from roots to leaves

     Supports leaves, fruits and flowers

     Food Storage

A celery stalk, the part of celery that we eat, is a special part of the leaf structure called a petiole. A petiole is a small stalk attaching the leaf blade of a plant to the stem.

In celery, the petiole serves many of the same functions as a stem. It's easy to see the "pipes" that conduct water and nutrients in a stalk of celery.

Here the "pipes" are dyed red so you can easily see them.

Leaves

Most plants' food is made in their leaves. Leaves are designed to capture sunlight which the plant uses to make food through a process called photosynthesis.

Blade  Main body of leaf

Petiole Attaches blade to stem

Midrib Large central vein

Apex    Tip of leaf

Base    Attaches to petiole, if petiole is absent attaches directly to stem 

Margin  Edge of leaf

 Epidermis  Responsible for gas and water exchange

Stomata Opening in epidermis where gas and water exchange

Mesophyll Middle layer of leaf where photosynthesis occurs

 

Important Functions of Leaves

Photosynthesis 

Process that plants use to produce their food

6CO2 + 6H2OþC6H1206 + 6 O2

Transpiration

Loss of water and exchange of carbon dioxide 

Flowers

Flowers are the reproductive part of most plants. Flowers contain pollen and tiny eggs called ovules. After pollination of the flower and fertilization of the ovule, the ovule develops into a fruit.

Flower Function

Sexual Reproduction is the flowers sole function

Pollination by:

 Wind

Insects and Birds

 Fruit

Fruit provides a covering for seeds. Fruit can be fleshy like an apple or hard like a nut.

Fruit Classification

Aggregate

Develop from a single flower with many ovaries

  Multiple

 Fruit develops from a group of tightly clustered flower

Simple

Develop from a single ovary

Seeds

Seeds contain new plants. Seeds form in fruit.

Parts of the Seed
  
*Embryo

Growing part of seed

*Endosperm

Tissue that provides nutrition for the developing seed

*Cotyledon

Food storage tissue

*Seed coat

Protective outer covering of the seed