Parts of the Plant and Their Function

Unit 3

The Importance of Plants

• Primary source of food

• Produce Oxygen

• Renew and cool the air, slow high winds, hold soil/prevent erosion, building materials and aesthetics.

4 Basic Parts of a Plant

• Leaves

• Stems

• Roots

• Flowers

Other Terms

• Petiole- leaf stalk of a plant.• Epidermis- single layer of cells which

protect the leaf from loss of too much moisture.

• Transpiration- when plants give off moisture and exchange gases such as oxygen and carbon dioxide.

• Respiration- consumption of oxygen and giving off carbon dioxide.

Internal Leaf Structure Terms

• Chloroplasts- small green particles containing chlorophyll found in leaves.

• Chlorophyll- green substance found in plants which gives color and necessary for photosynthesis.

How Photosynthesis Occurs

• Photosynthesis- process by which Carbon Dioxide and Water in the presence of light are converted to Sugar and Oxygen.

Chemical Equation for Photosynthesis

• 6 CO2 + 6H20 + 672kcal= C6H12O6 + 6O2• Carbon dioxide + water + light energy = Sugar + Oxygen

2 Main Functions of Stems

• Movement of water and minerals from roots upward to the leaves and the movement of manufactured food from the leaves down to the roots.

• Support leaves and reproductive structures.

Other Plant Terms

• Xylem- transports water and nutrients from the roots to the stem and leaves.

• Phloem- transports food from leaves through the stem to the roots.

More Terms

• Cambium- produces all new cells.

• Monocot- have only one cotyledon (seed leaf).

• Dicot- plants having two seed leaves.

• Cotyledon- first leaves to appear on a plant.

Main Functions of the Roots

• Anchor plant and hold it upright.

• Absorb water and minerals from the soil.

• Store large quantities of plant food.

• Propagate or reproduce some plants.

• Root cap- continuously produces all new cells as it pushes its way through the soil.

• Root hairs- absorbs moisture and minerals which are conducted to the larger roots and to the stem of the plant.

Fibrous Root System vs. Tap Root System

• Figure 3.11 Those plants with fibrous root systems consist of many smaller roots spread out over the soil profile.

• Those plants with tap roots stand a greater chance of damage as a result of transplanting.

How are seeds produced?

• ANSWER- through a sexual process with a male and female parent involved.

• Complete flower- has both male and female parts.

• Figure 3.12 (Parts of a complete flower)

• Draw and list parts

4 Main Parts of a Complete Flower

• 1 Sepal

• 2 Petal

• 3 Pistil

• 4 Stamen

Definitions

• Sepals- the green leaf like parts of the flower that cover and protect the flower bud before it opens.

• Petals- act to attract insects for pollination.

• Stamen- male reproductive part of flower.a. Filament- short stalk of stamen.

b. Anther- contains pollen (male sex cell).

Female Parts of a Flower

• Pistil- female part of flower.

a. Ovule- female sex seed or egg.

b. Stigma- catches pollen.

c. Style- tube that leads to ovary.

d. Ovary- egg cell develops in ovary. After fertilization, the ovary grows to become a fruit or seed.

Incomplete Flowers

• Those that have only the male or female reproductive parts, not both.