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,

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.