1. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Plant Reproduction and Growth Chapter 18 Copyright © McGraw-Hill Companies Permission required for reproduction or display

2. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Outline Angiosperm Flower  Structure  Reproduction  Life Cycle  Seeds  Fruit  Germination  Hormones  Tropisms

3. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies The Angiosperm Flower Developing gametophyte generation completely enclosed within parent sporophyte.  Pollen grains develop from microspores.  Embryo sac develops from megaspore. Male and female structures usually occur together in same individual flower. Reproductive structures are not permanent parts of adult individual.

4. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies The Angiosperm Flower  Flower Structure  Composed of Whorls - Outermost - Sepals (Calyx) - Second - Petals (Corolla) - Third - Stamens (Androecium)  Anther - Fourth - Carpel (Gynoecium)  Stigma, Style, Ovary

5. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Structure of Angiosperm Flower

6. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Angiosperm Reproduction Pollen grains develop from microspores formed in pollen sacs located in the anther. Eggs develop in ovules, and each ovule contains a megaspore mother cell.  Usually only one mother cell survives. Pollination - Transferring pollen to stigma.  Self-Pollination  Pollinators often drawn to nectar  Wind

7. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Angiosperm Reproduction Fertilization  Pollen adheres to stigma and begins to grow pollen tube that pierces the style, and eventually reaches ovule.  Double fertilization - two sperm cells used forming embryo and endosperm.

8. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Angiosperm Life Cycle

9. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Seeds In early development of angiosperm embryo, embryo stops developing and becomes dormant as a result of drying.  Outermost covering of ovule develop into seed coat enclosing dormant embryo and a stored food source. - Most metabolic activities cease. Germination - Resumption of metabolic activities that leads to growth of mature plant.

10. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Angiosperm Embryo Development

11. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Fruit During seed formation, flower ovary begins to develop into fruit.  Fleshy fruits often dispersed by vertebrates. - Excretion via solid waste.

12. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Germination Resumption of metabolic activities and growth often trigged by water.

13. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Plant Hormones Differentiation in plants is largely reversible.  Following germination, further development depends on activities of meristematic tissues, and environmental interaction. Copyright © McGraw-Hill Companies Permission required for reproduction or display

14. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Plant Hormones Hormones are produced in small quantities and transported to another part of an organism to stimulate physiological processes.  Produced in non-specialized tissues. - Auxin - Cytokinins - Gibberellins - Ethylene - Abscisic Acid

15. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Auxin Regulates cell growth in plants, such as that controlling phototropism.  Cells in sunlight elongate more than those in shade.  Synthetic auxins used to control weeds. - 2,4-D - 2,4,5-T

16. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Copyright © McGraw-Hill Companies Permission required for reproduction or display

17. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Other Plant Hormones Cytokinins  Stimulates cell division and determines course of differentiation.  Promote growth of lateral buds and inhibit formation of lateral roots. Gibberellins  Play major role in stem elongation.

18. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Other Plant Hormones Ethylene  Gas that hastens fruit ripening.  Can accelerate abscission of leaves or fruits damaged by various stressors. Abscisic Acid  Stimulates leaves to age rapidly and fall off.  May induce formation of winter buds.

19. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Photoperiodism and Dormancy Photoperiodism - Mechanism by which organisms measure seasonal changes in relative day and night length.  Flowering Responses - Long-day plants - Short-day plants - Day-neutral plants

20. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Photoperiodism and Dormancy Chemical Basis of Photoperiodism  Phytochromes  Flowering Hormones Copyright © McGraw-Hill Companies Permission required for reproduction or display

21. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Tropisms Tropisms - Growth responses of plants to external stimuli.  Phototropism - Growth towards directional sources of light.  Gravitropism - Stems grow upward and roots downward.  Thigmotropism - Response of plants to touch.

22. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Review Angiosperm Flower  Structure  Reproduction  Life Cycle  Seeds  Fruit  Germination  Hormones  Tropisms

23. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies Copyright © McGraw-Hill Companies Permission required for reproduction or display