Structures of a Flowering Plant6.4.2: Summarize the basic

functions of the structures of a flowering plant for defense, survival, and reproduction.

Discuss

How do plants protect

themselves?

Essential Question

What are some of the structures plants use for defense and survival?

?

Structures for defense

Plants have structures for defense that protect them from threats and without these defenses the plant might die. Examples of natural defenses that plants have developed over time may be:

Structures for defense

• thorns that can defend the plant from being eaten by some animals or destroyed by others.

Structures for defense

• fruits and leaves with poisons so that they are not eaten by animals.

Structures for defense

• the ability to close its leaves when touched (thigmotropism).

How do thorns defend a plant?

Write down 3 poisonous plants.

How can thigmotropic plants defend themselves?

https://www.youtube.com/watch?v=BLTcVNyOhUc

Structures for Survival

Plants have structures that allow them to survive in their habitats when the conditions are not suitable. Examples of parts of flowering plants that function for survival may be:

Structures for Survival: Leaves

• Leaves are important because they are the site of:– Photosynthesis (when plants make sugar for food)– Respiration (when plants break sugar down for energy)– Transpiration (when plants release water vapor into the

atmosphere) This is a review term.

Photosynthesis

HOW HAVE THE LEAVES OF THIS PLANT ADAPTED FOR SURVIVAL?

Is this also considered thigmotropism?

Structures for Survival: StemsStems support the plant and hold the leaves up to the light. Stems also function as food storage sites.• Xylem transports water from

roots to leaves & other parts of plant.

• Phloem transports food made in leaves to growing parts of plant.

Structures for Survival - Roots

Roots• Anchor the plant• Absorb water & nutrients

from the soil• Store extra food

The more surface area on the root, the more water & nutrients it can absorb.– Root hairs help to increase the surface area.

Structures for Survival – RootsTwo Types

• Fibrous Roots: several main roots that branch off to form a mass of roots. Ex. Grass, corn, some trees.

• Taproots: One large, main root w/ smaller roots branching off. Ex. Carrots, dandelions, cacti,

Structures for Survival: Seeds

• Seeds have special structures that allow them to be dispersed by wind, water, or animals.

• The seeds coat helps protect the embryo from injury and also from drying out.

How Seeds Disperse

Summary

Answer the essential question.

• What are some of the structures plants use for defense and survival?

Answer…• Defense

– Thorns– Toxins (poisons)– Thigmotropism (movement)

• Survival– Leaves– Stems– Roots– Seeds

Online Interactive Activity

• Play the Plant Defenses GamePlants evolve to suit their surroundings and to

compensate for any hazards around.Objective: Survive.http://revolution.caret.cam.ac.uk/flash/defence.swf