Plants and Their Adaptations

1. Plants and Their Adaptations Variations of Parts Roots Leaves Seed Dispersal Attraction of Pollinators Phototropism Geotropism

2. Survival • As you watch this presentation, focus on how variations, adaptations, or behaviorsenhance a plants’ survival. Include: Roots Seeds StemsPhototropism LeavesGeotropism Flower

3. Variations • Variation is: • the difference between individuals of the same species • the process or act of changing • Variation is necessary: • If all of the plants in a species were exactly the same, they could all be taken out by disease or disaster.

4. Structure and Function Comparing structure and function of parts and behaviors helps us understand why variation is necessary. • Structure is the form of an organism’s parts. • Example: A pedal is structured like a landing strip for insects. • Function is what that part does. • Example: The function of a petal is to attract insects. http://commons.wikimedia.org/wiki/File:Mature_flower_diagram.svg

5. Common Plant Parts • Most plants, no matter how they look, share some common parts. • Most plants have: • Roots • Stems • Leaves • Flowers http://commons.wikimedia.org/wiki/File:Leaves-scan.jpg

6. Structure and Function • The structure and function of plant parts show evidence of adaptation. • Examples Include: • Defenses against consumers • Ways to attract pollinators • Seed dispersal to ensure survival http://commons.wikimedia.org/wiki/File:Weberocereus_tunilla_-_The_Cactaceae.jpg

7. Roots Roots must adapt to their different environments. • Structure and Function: • Roots act as anchorsto keep plants grounded. • Roots take in water and minerals from the soil through tiny root hairs. • Some roots can store food. http://commons.wikimedia.org/wiki/File:Cycads_root.png

8. Roots Some roots spreadout along the ground in search of water in places where it rains often. http://commons.wikimedia.org/wiki/File:Root.png

9. Roots Some roots grow deeper into the ground in search of water in places where the climate is dry. http://commons.wikimedia.org/wiki/File:Root_rot_in_cicer_arietinum_(hydro-grown).jpg

10. Roots Roots Some roots begin on a stemrather than below the ground. They are used for supportto prop or brace the plant. Soil http://commons.wikimedia.org/wiki/File:Ghana_roots.JPG

11. Roots Some plants are able to store food in their roots for later use. These are called storage roots. • Some examples include: • sweet potatoes • carrots • beets • radishes http://commons.wikimedia.org/wiki/File:Rabano-radish-raphanus-sativus.jpg

12. Stems Stems must adapt to whatever environmentthe plant is in. • Functions: • Hold the plant uprightand support the leaves • Carry water upthe plant and food downfrom the leaves to other parts of the plant • Defendplants: thorns, prickles, and stinging hairs http://commons.wikimedia.org/wiki/File:Cirsium_undulatum_(4990344551).jpg

13. Stems Many stems are edible like asparagus, broccoli, cauliflower, and celery. Cinnamon: The bark is used as a spice. Garlic and Onion: They are bulbs. Ginger Root: The edible portion is a branched underground stem called a rhizome. Potato: The edible portion is an underground stem that is also a tuber. Sassafras Tree: The shoots and stem bark can be used to make root beer. http://commons.wikimedia.org/wiki/File:Dracaena_sanderiana_close_up.jpg

14. Leaves Leaves have many shapesand sizes, all depending on the environment and how much sunlight the plant needs. http://commons.wikimedia.org/wiki/File:Leaves-scan.jpg

15. Leaves • Functions: • Make food through photosynthesisand release oxygen • Protectthe plant: prickles and spines http://commons.wikimedia.org/wiki/File:Photosynthesis.gif

16. Leaves Notice how some leaves have adapted to function as a defense. http://commons.wikimedia.org/wiki/File:Erythrina_zeyheri,_blaarstekels,_Krugersdorp.jpg

17. Flowers • Functions: • A flower helps the plant reproduce. • The flower contains the pollen and egg necessary to make a fruit which has the seeds in it.

18. Structure of a Flower

19. Seeds • Seeds disperse differently depending on their structure: • Wind: Flowers can have a wing-like structure. • Water: Flowers can have water-proofcovering. • Animals/Humans: Flowers can have burrs for sticking to fur or clothing. • Insects: Pollen sticks to insects as they move from place to place. • Some seeds can split and twist to throwseeds in all directions.

20. Seeds Wind: Maple seeds have a wing-like structure. Insects: Pollen sticks easily to this bumble bee. http://commons.wikimedia.org/wiki/File:Bumble_Bee_Gathering_Pollen.jpg http://commons.wikimedia.org/wiki/File:Maple-seed.jpg

21. Seeds Water: The Heritiera littoralis seed has a water-proof covering. Animals: This bison’s face is covered in cockleburs, which are the Velcro®-like seed pods. http://commons.wikimedia.org/wiki/File:Flickr_-_Furryscaly_-_Burface.jpg http://commons.wikimedia.org/wiki/File:Sundari_seed.JPG

22. Phototropism Directional growth in response to the direction of the light source. • Positive Phototropism: growth towards a light source • Plant shoot leaves exhibit positive phototropism • Negative Phototropism: growth away from light source • Roots usually exhibit negative phototropism. http://commons.wikimedia.org/wiki/File:Phototropism.jpg http://commons.wikimedia.org/wiki/File:Sunlight_on_Beech_roots_-_geograph.org.uk_-_1609346.jpg

23. Geotropism Turning by a plant in response to gravity • Charles Darwin documented the following: • Stems show negative geotropism • (grow in opposite direction of gravitational • pull) • Roots show positive geotropism • (grow in direction of gravitational pull) http://commons.wikimedia.org/wiki/File:Root_rot_in_cicer_arietinum_(hydro-grown).jpg

24. Sweet Potato Plant This plant was sprouted in a shallow bowl of water in a kitchen. The leaves on the main sprout were facing the window and are reaching toward the light. The leaves on the secondary sprouts are bending toward the light because they were facing away from the window. The roots are reaching downward toward the ground. They are filling the bowl but always trying to go downward.