Introduction to Plant Biology - Fog.ccsf.edu

Botany 10 Dr. Bibit Traut Spring 2011Lecture 1: Introduction to Plant BiologyEcological Services• Sources of food, fabric, shelter, medicine• Produce oxygen & organic nitrogen• Decompose & cycle essential nutrients• Build land• Inhibit erosion• Control atmospheric temperatureImportance of Plants to Humans• Food & beverages• Trees for lumber• shelter• Warships• paper• Fuel• smelt metals• cure pottery• generate power/heat• Sources of wealth• spices• agriculture• Sources of industrial products• rubber• OilWhat is a Plant?• Autotroph• Characterized by:• Sessile• Cell wall of cellulose• Multicellular body• Control water loss• Strengthening tissues• Reproduce sexually/asexuallyPlants figurePlant Cells• Possess basic characteristics of life:• Movement• Metabolism (photosynthesis, respiration, assimilation)• Grow & reproduce• Respond to environment• Complex organization (molecules, organelles, cells, tissues, organs)

Botany 10 Dr. Bibit Traut Spring 2011Proteins• regulate chemical reactions in cells, important structural components• Consist of chains of amino acids• Amino acids contain:• Amino group (-NH 2 )• Carboxyl group (-COOH)• R-groupLipids• Fatty or oily substances, mostly insoluble in water• Contain C, H, O (less oxygen than carbohydrates)• Make up plasma membranesNucleic Acids• Vital to internal communication & cell functioning• Building blocks of DNAWater• Most abundant molecule in living organisms• Important characteristics• Ability to dissolve many compounds• Remains liquid over wide temperature range• Forms weak hydrogen bonds with itself & other moleculesSeparating Inside from Outside• Plasma membrane• Selectively permeable lipid membrane• Surrounds cell• Controls transport into/out of cell• Cell wall• Composed of cellulose (polysaccharide), some with lignin• Functions:• structural strength• limit water absorption• protectionVacuoles• Large compartment surrounded by single membrane• Functions• stores water• regulates turgor pressure inside cell• stores nutrients (e.g. sucrose)• accumulates toxic compounds (anti-herbivore)• waste storage

Botany 10 Dr. Bibit Traut Spring 2011Organelles of Protein Synthesis & Transport• Nucleus• Ribosomes• Endoplasmic Reticulum• Dictyosomes (Golgi Apparatus)• Chloroplasts• MitochondriaOrganelles of Energy MetabolismBotany As A Science• Science involves the observation, recording, organization, and classification ofinformation.• Study plants for many reasons:• Practical• Applied• Theoretical• Initially interest in plants was practical/appliedScientific Inquiry• Inquiry• A search for information and explanation, often focusing on specific questions• Process of observation & hypothesis testing• Hypothesis (“prediction”)• “tentative answer to a well-framed question, an explanation on trial”• testable• falsifiableTheories in Science• A scientific theory• Is broad in scope• Generates new hypotheses• Is supported by a large body of evidenceThe Study of Plants• Plant Anatomy: internal plant structure• Plant Physiology: plant function• Plant Morphology: plant form & structure• Plant Taxonomy & Systematics: plant classification & evolutionary relationships• Plant Geography: plant distributions• Plant Ecology: interaction of plants & their environment• Economic Botany & Ethnobotany: practical plant use

Botany 10 Dr. Bibit Traut Spring 2011Why Study Plant Biology?• Show interrelationships between plants & other fields of study• Prepare for careers in plant biology• Gain fundamental knowledge for upper division plant biology courses• Share expertise gained with nonbotanists• etc…Challenge for 21 st CenturyWhile the human population increases, the major challenge of retaining naturalbiological diversity and developing a sustainable use of the world’s forests,grasslands, and cropland remains. As you study plant biology, think of the waysthat you can contribute to this challenge.