Rapid Learning Center Presents. Teach Yourself AP Biology in 24 Hours. Plant Function. AP Biology Rapid Learning Series

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1 Rapid Learning Center Chemistry :: Biology :: Physics :: Math Rapid Learning Center Presents Teach Yourself AP Biology in 24 Hours *AP is a registered trademark of the College Board, which does not endorse, nor is affiliated in any way with the Rapid Learning courses. Plant Function AP Biology Rapid Learning Series Wayne Huang, PhD Andrew Graham, PhD Elizabeth James, PhD Casandra Rauser, PhD Jessica Habashi, PhD Sara Olson, PhD Jessica Barnes, PhD Rapid Learning Center Rapid Learning Inc. All rights reserved. Rapid Learning Inc. All rights reserved. :: 1

2 Learning Objectives By completing this tutorial, you will learn about: Plant Nutrition Plant Hormones Plant Defense Plant Reproduction 3/42 Plant Function Concept Map Soil Plant Growth Plant reproduction Air Insects pathogens Regulated by Plant Hormones Flower structure Auxin Cytokinins GAS Ethylene ABAs Seed Development Phototropism Gravitropism Apical Dormancy Growth promotion 4/42 Rapid Learning Inc. All rights reserved. :: 2

3 Plant Nutrition Plants obtain their nutrients from soil and air. 5/42 Plant Nutritional Sources The major source of plant nutrition is fixation of atmospheric CO 2 using photosynthesis to produce simple sugar. Photosynthesis is the source of energy to make sugars. Soil and water are also sources of nutrition. They provide an anchorage as well as minerals and nutrients. 6/42 Rapid Learning Inc. All rights reserved. :: 3

4 Nutrient Classes Nonmineral nutrients from air and water, carbon, hydrogen and oxygen. Mineral nutrients from soil include macronutrients which are required in large quantities. Micronutrients are required in small quantities. 7/42 Macronutrients Primary macronutrients include: nitrogen, phosphorus and potassium. Secondary macronutrients include: calcium, magnesium and sulfur. Potassium Nitrogen Phosphorus Primary Magnesium Calcium Sulfur Secondary 8/42 Rapid Learning Inc. All rights reserved. :: 4

5 7 Micronutrients There are 7 micronutrients. These are needed in small amounts. Copper (Cu) Zinc (Zn) Iron (Fe) Boron (B) Chloride (Cl) Molybdenum (Mo) Manganese (Mn) 9/42 Obtaining Nutrients Macronutrients are usually not sufficient in cultivated soil and need to be added as fertilizer. Plants get nutrients from soil (roots) or air (leaves and stems). Natural plant communities recycle nutrients for use by other organisms. 10/42 Other ways to get nutrients include: Nitrogen fixation by bacteria. Carnivorous feeding. Symbiotic association with fungi. Parasitic plants. Rapid Learning Inc. All rights reserved. :: 5

6 Transpiration Transpiration is the evaporation of excess water from aerial parts of a plant. This is done by leaves, stems, flowers and fruits. Root absorbs minerals and water from soil Water and solute are transported up through plants via xylem The driving force is the evaporation from leaves via guard cells This process is called transpiration 11/42 Transportation of Carbohydrates Leaves make carbohydrates to support plant life sugar source Carbohydrates are transported down via phloem in vascular tissue to where they can be used sugar sink 12/42 Rapid Learning Inc. All rights reserved. :: 6

7 Plant Hormones Plant Growth and Development 13/42 Plant Hormones Five major types of hormones that control plant growth and development. 1. Auxin 2. Gibberellins (GA) 3. Cytokinins 4. Ethylene 5. Abscisic Acid (ABA) A hormone is a chemical messenger between cells. They signal target cells to change a physiological activity. 14/42 Rapid Learning Inc. All rights reserved. :: 7

8 Auxin Auxins are produced by apical tissues and developing leaves and they stimulates downward growth. Auxins function at the cell level by stimulating cell elongation and cell division. The most important auxin is indole-3-acetic acid (IAA). 15/42 Auxin Functions Auxins are plant hormones that are involved in the coordination of many growth and behavior processes in the plant s life cycle. Auxin Auxins are used to promote the growth of roots as well as flowering, setting fruits and preventing premature fruit drop. Auxins act by stimulating or inhibiting the expression of specific genes. 16/42 Rapid Learning Inc. All rights reserved. :: 8

9 Apical Dominance Apical dominance is the inhibition of lateral buds by auxin from the apical bud. Auxin is broken down as it moves down stem, so its concentration decreases. Removal of apical bud releases apical dominance Dormant lateral bud Apical bud removed 17/42 Phototropism Phototropism: when illuminated from one direction, the shoot proceeds to grow in that direction. When illuminated, Auxin accumulates on the shady side of a plant This stimulate elongation of cells from the shady side and bend the plant to the light 18/42 Rapid Learning Inc. All rights reserved. :: 9

10 Gravitropism Plant growth and its movements respond to gravity. This is known as gravitropism. When a plant is put into a horizontal position plant shoots will bend upward because auxin accumulates on the lower part of the stem called negative gravitropism. 19/42 Plant roots will respond by bending down which is known as positive gravitropism. This is because of the accumulation of starch granules in the root caps. Cytokinins Adenine Derivatives Cytokinins stimulate plant cell differentiation. Notice the difference in these two plants of treated versus untreated. Cytokinin Function Stimulate cell division Major source: roots and apical meritstem Opposite to auxin: 1)Move upward; 2) promote growth of lateral buds Prevents leaf senescence Essential for plant cell culture. 20/42 Rapid Learning Inc. All rights reserved. :: 10

11 Gibberellins Gibberellins promote stem elongation, as well as in bolting which is sudden stem elongation. It breaks the dormancy of seeds and stimulates flowering mature plants. 21/42 There are more than 30 structurally related compounds. Abscisic Acid It is a major plant stress hormone. Abscisic acid is a plant hormone involved in adscission (shedding) of plant parts and in bud dormancy. Abscisic acid is involved in the closing of stomata. It inhibits fruit ripening and encourages seed dormancy by inhibiting cell growth. 22/42 In winter preparation abscisic acid is produced in the terminal buds and slows growth and protects buds during the cold. Rapid Learning Inc. All rights reserved. :: 11

12 Ethylene The only gas form of plant hormone, produced by fruit. Function Promote fruit ripening Stimulates senescence and abscission in leaves and fruits Minor functions: Sprouting of potato buds; Seed germination; Flower formation in some species H2C=CH2 Ethylene 23/42 What Plant Hormone Trigger Growth? Do you know what plant If you said auxin, hormone is involved in cytokinin and promoting growth? gibberellins you are right. 24/42 Rapid Learning Inc. All rights reserved. :: 12

13 Plant Defense How plants cope with stress and insects 25/42 Plant Defense There are two basic strategies of plant defense: physical and chemical barrier. Physical barriers against herbivores include: Cuticle: a layer of wax on the surface of leaves Trichomes: extension of plant cells Spines which are modified leaves. Bark 26/42 Chemical barriers: secondary metabolites or chemical toxins that could cause problems for the predator. These chemicals include isoprenes, phenolic compounds and alkaloids. Rapid Learning Inc. All rights reserved. :: 13

14 Systemin Response Plant response to wound: systemin Synthesis of Synthesis of Systemin Proteinase inhibitors Plants under attack Systemin is a signal molecule for plants to sense the wound and triggers a series of biochemical reaction to release proteinase inhibitors which are toxic to insects. 27/42 Plant Defense to Pathogens Virus Infection Cell Death Hypersensitive Response (HR) Gene-for-Gene Theory To every pathogen avirulence (avr) gene, there is a corresponding R gene (resistance gene) in plant to trigger HR 28/42 HR is commonly followed by a slower response that leads to systemin acquired resistance (SAR). SAR occurs when a hormone, which may be salicylic acid, travels from the infection site to nearby tissues and triggers the expression of a specific set of genes. Rapid Learning Inc. All rights reserved. :: 14

15 How Does a Plant Respond to Injury? How do plants respond to being wounded? It mounts a systemin response involving signaling from systemin. 29/42 Plant Reproduction 30/42 Rapid Learning Inc. All rights reserved. :: 15

16 Sexual and Asexual Reproduction Yes, sexual reproduction involves male gametes (sperms) and female gametes (eggs) which combine to create a zygote. Plants can reproduce asexually and sexually. In asexual reproduction offspring are produced by mitosis and are genetically identical to the parent. Female structures house the embryo during development. 31/42 Life Cycle of a Flowering Plant Seed production Seeds Seed germination Adult plant with flowers 32/42 Pea plant Seedling Rapid Learning Inc. All rights reserved. :: 16

17 Flowers are Reproductive Organs Pedal Stigma Carpel Ovary (female organs) Anther Filament Steman (male organs) Sepal 33/42 Formation of Gametes Microspores --> Pollens Megaspores --> Eggs Pollen Mother Cell 2N Meiosis Pollen Pollen Grain Grain Pollen Pollen Grain Grain 1N Pollen grain in anther 1N Meiosis Mother Cell (2N) 3 megaspores degenerate, 1 survives 3 times mitosis then cell dividing 1N egg cell 2N central cell 1N egg cell Embryo sac in ovary 34/42 Rapid Learning Inc. All rights reserved. :: 17

18 The linked image cannot be displayed. The file may have been moved, renamed, or deleted. Verify that the link points to the correct file and location. AP Biology Rapid Learning Series - 18 Pollination Pollination: Pollen from male organs are transferred to surface of stigma Sperms meet megaspores (eggs) 1 Self-pollination 2 Self-pollination, same plant but different flower 3 Cross-pollination Different plants 35/42 Formation of Zygotes Pollen tube grows, two sperm cells are delivered into ovary One sperm fertilize one of the 6 eggs, one fertilizes the central cell Fertilized egg develops into 2N zygotes and fertilized central cell develop into endosperm (3N) Zygotes attach to parental plant to acquire nutrients which is to be stored in cotyledons Ovary 1N 1N 1N Central cell (2N) Egg cell (1N) 1N 1N 1N 3N 3N 3N 3N Endosperm (3N) Embryo (2N) 2 sperm nuclei 36/42 Pollen tube Double pollination Rapid Learning Inc. All rights reserved. :: 18

19 Seed Structure Zygotes grow and differentiate, acquiring and store food in cotyledons and seed forms. 37/42 How are Seeds Developed? Double pollination. Pollination of eggs forms the embryo. How does a seed develop? Acorn 38/42 Pollination of the central cell forms the endosperm Rapid Learning Inc. All rights reserved. :: 19

20 Question: Review is the evaporation of excess water from aerial parts of a plant. Transpiration Auxins stimulate t Downward growth. is the inhibition of lateral buds by auxin from the apical bud. stimulate plant cell differentiation. Apical dominance Cytokinins 39/42 promote stem elongation and bolting. Gibberellins Learning Summary Plant nutrients Macronutrients micronutrients Plant defense Natural barrier Against wound Against pathogen Plant reproduction Flowers Zygotes Seeds Plant growth and development Plant hormones 40/42 Rapid Learning Inc. All rights reserved. :: 20

21 Congratulations You have successfully completed the core tutorial Plant Function Rapid Learning Center 41/42 Rapid Learning Center Chemistry :: Biology :: Physics :: Math What s Next Step 1: Concepts Core Tutorial (Just Completed) Step 2: Practice Interactive Problem Drill Step 3: Recap Super Review Cheat Sheet Go for it! 42/42 Rapid Learning Inc. All rights reserved. :: 21