Chapter 1What is Biology?So what exactly is life?Slide 4The characteristics of life:Slide 6Each level has ingredients or components which interact to make something greater than the sum of the parts.Slide 8Slide 9Slide 10If you put a plant in your window, the stem will lean in the direction of the sun. This is an example of which characteristic of life?Response to stimuliOur body works to keep our temperature at about 98.6ºF. This is an example of which characteristic of living things?HomeostasisAbility to acquire material and energyOrganisms can take in nutrients (food) for raw materials and energy (heterotrophs)The word heterotroph means “other-feeder” or:Metabolism changes the raw material and energy into the forms which are needed for maintenance, growth, reproduction, etc . Metabolism is basically the sum total of all of the chemical reactions that occur within an organism.Slide 19Slide 20The genetic information for “How to build an offspring” is stored in the DNA of the parent(s) and that information is passed on to the offspring.EvolutionThe evolutionary changes are usually slow, taking several generations and occur by the accumulation of DNA changes known as mutations.All life forms have these characteristics in common, yet there is an amazing diversity in the forms of life on the planet.All living organisms are organized into groups.There are two prokaryotic domains; Bacteria and Archaea and a eukaryotic domain; Eukarya.In the figure, which organism is most closely related to humans?Within the domains are at least 6 groups known as kingdomsThe first difference is cell typeSlide 30The next property is how many cells the organism hasSlide 32The third attribute in the classification of organisms at the kingdom levels is how the organism obtains nutrients/energySlide 34Chapter 1An Introduction to Life on EarthWhat is Biology?--- The science of living organisms and life processes.So what exactly is life?Life: An evanescent phenomenon dependent for its continued existence, andperpetuation, on cyclic enzymatic reactions in an environment consistingprincipally of protein and water. Student Dictionary of Biology. (1972) Van Nostrand Reinhold Company, New York. Life: the property by which living organisms are distinguished from dead Organisms or inanimate matter. Websters II New Riverside Dictionary.These definitions suck terribly.Neither of the Biology texts (for majors or non-majors) that we use include the term “life” in their glossaries.The characteristics of life:1. Complex, organized structure2. Response to stimuli - a change outside (or inside) leads to another change3. Homeostasis - the ability to maintain the structure and regulate the internal environment.4. Ability to acquire material and energy -The material and energy are often transformed5. Growth6. Reproduction - either sexual or asexual DNA is genetic information, the “blueprint” for the offspring7. Ability to evolve - to change to fit the environmentComplex, organized structureThe complexity of life is built in levels. Fig. 1-8Each level has ingredients or components which interact to make something greater than the sum of the parts.Emergent PropertiesExample: NaCl (Sodium Chloride)Sodium = solid metalChlorine = poisonous gasPut them together = table saltBiosphereEcosystemCommunityThat part of Earth inhabitedby living organisms; includes boththe living and nonlivingcomponentsA community together with its nonliving surroundingsTwo or more populations of differentspecies living and interacting inthe same areaEarth's surfacesnake, antelope, hawk, bushes, grass, rocks, stream snake, antelope, hawk, bushes, grassherd of pronghorn antelopePopulationMembers of one species inhabiting the same area SpeciesVery similar, potentially interbreeding organismsFig. 1-1MulticellularOrganismOrgan SystemOrganTissueCellA structure usuallycomposed of several tissuetypes that form a functional unitAn individual living thing composedof many cellsTwo or more organs working together in the execution ofa specific bodily functionA group of similar cells that performa specific functionThe smallest unit of lifenerve cell nervous tissuethe brainthe nervous systempronghorn antelopeFig. 1-1OrganelleMoleculeAtomSubatomicParticleParticles that make up an atomThe smallest particle of an elementthat retains the properties ofthat elementA combination of atomsA structure within a cell thatperforms a specific functionmitochondrionwaterhydrogen carbonglucosechloroplast nucleusDNAnitrogenoxygenelectronneutronprotonFig. 1-1If you put a plant in your window, the stem will lean in the direction of the sun. This is an example of which characteristic of life?•Living things are organized.•Living things respond to stimuli.•Living things maintain homeostasis.•Living things need energy.Response to stimuliOrganisms react to external and internal stimuli.Some reactions are slow and can’t be seen.Our body works to keep our temperature at about 98.6ºF. This is an example of which characteristic of living things?•Living things are organized.•Living things respond to stimuli.•Living things maintain homeostasis.•Living things need energy.Homeostasis -the ability to maintain the structure and regulate the internal environment.In order to stay alive and function, organisms must keep the conditions within their bodies fairly constant.Ability to acquire material and energy The material and energy are often transformed . Energy is used to maintain a high level of complexity and organization, to grow, and to reproduce.Organisms can take in nutrients (food) for raw materials and energy (heterotrophs) Or they can use sunlight for energy (photosynthesis) to produce energy-rich sugar molecules (autotrophs)The word heterotroph means “other-feeder” or:•Able to photosynthesize.•Able to make its own food.•Must rely on other organisms for energy.•Make its own energy.Metabolism changes the raw material and energy into the forms which are needed for maintenance, growth, reproduction, etc .Metabolism is basically the sum total of all of the chemical reactions that occur within an organism.GrowthAll organisms grow during their lifeReproduction Individuals reproduce their own kind.The genetic information for “How to build an offspring” is stored in the DNA of the parent(s) and that information is passed on to the offspring.Fig. 1.6Evolution If the environment
View Full Document
Unlocking...