Biology is the study of LifeCharacteristics of LifeBiology is the study of Life What is life? What is living on not?When does life begin? When does it end?Characteristics of Life1. Emergent Properties:a. The sum is greater than the individual partsb. At higher levels of organization, new and greater properties emerge as a result of interactions among components at lower levelsc. Hierarchy of Organization1. Atoms-units of structure and function of matter2. molecules-two or more atoms chemically combined3. macromolecules: a. carbohydratesb. proteinsc. lipidsd. nucleic acids4. cellular organelles-membranes-nucleus-mitochndria5. Cells- Basic Unit of Structure andfunction of all life.a. Prokaryotic- small cells w/o nuclei -Bacteria -Archeab. Eukaryotic-large, complex, cells have nuclei and organelles-unicellular -Protists-multicellular-Plants-Fungi-Animals6. Tissues- composed of a group of cells with a common functiona. Epithelialb. Connectivec. Muscled. Nervous7. Organs-composed of tissues that together perform a higher level function.8. Systems-composed of specific organs that work together.9. Organism- the living ‘thing’10.Population- A unit composed of organisms of the same species.Species-organisms that have the same number and kind of chromosomes and produce fertile offspring.-pop. is the unit of evolution11.Communities-composed of several populations of different species that live and interact in close proximity.12.Ecosystem- composed of biotic and abiotic factors. 13.Biomes- major ecosystems defined by climate andvegetation which maintain life.-Tropical Rain Forest-Deserts-Everglade-Taiga14.Biosphere- all the areas of the planet that support life.-Each level of biological hierarchy of organization has emergent properties, whichresult from the interaction between components.-The highly organized nature of living organisms defies the 2nd Law of Thermodynamics, which states that the universe is progressing towards greater Entropy or disorder.2. Structure is related to function. a. In Nature if something works well it is repeated across many organisms. b. In general, the simplest structure whichrequires the least building blocks and energy to function is preferred.3. Organisms interact with each other and their surroundings (biotic & abiotic). a. Organisms are Open Systems that exchange materials and energy with their surroundings and each other. Ex. Food Chains (cycling of nutrients & energy flow)4. Dynamic balance is maintained in living systems through regulatory mechanisms.a. Feedback loops self regulate and maintain organisms and biological systems.-Negative feedback inhibits or slows a process-Positive feedback enables or speed a processb. Homeostasis is the maintenance of the internal steady-state or optimal range. Ex. PH, temperature, concentrations c. Irritability enables organisms to sense external and internal stimuli and react ensures survival.5. Heritable Information The continuity of life depends on the inheritance of biological information form parent to offsprina.DNA (deoxyribonucleic acid) encodes genetic instructions in its nucleotide sequence.-RNA (ribonucleic acid) is the hereditary substance in some virusesb. The diversity of life is achieved by different expressions of a common genetic language for programming biological structure, function, and order. All life forms employ a commongenetic code. -There is Unity in Diversityc.The entire “library “ of genes that an organism has is its Genome. Ex. Human genome is 3 billion bases long.6. Diversity and Unity are dual faces of life on Earth.a. Millions of different types of organisms exist.b. Organisms are classified by similarity into 3 domains: Bacteria-prokaryotic cellsArchaea-prokaryotic cellsEukarya-eukaryotic cellsc. Further divided into kingdomsd. Kingdoms are divided as follows:d. Domain Eukarya has 4 kingdoms 1.Protista-unicellular2.Plantae-multicellular, photosynthetic 3.Fungi-multicellular, decomphsers 4.Animalia-multicellular, heterotrophic-Unity exists in structures that are similar inmany organisms, such ascells---mitochondria---glycolysis-Diversity exists due to adaptation to a way of life or niche-Evolution a change in genetic instructions, leading to changes in structure and function“adaptations” that ensure survival, explainsdiversity and unity.7. Evolution The core theme of biology, a unifying thread that ties all life.a. Evolutionary connections among organisms explain the unity and diversity of life.b. Charles Darwin proposed a theory of Evolution: Survival of the fittestthrough Natural Selection in The Origin of Species, 1859.1. Contemporary species arose from a succession of ancestors though “Descent with modification” 2. The mechanism of evolution is natural selection.a. individuals of a population vary in many heritable traits. (gentic diversity) b. populations have a reproductive potential greater than what the environment can support.c. there is a struggle for existenced. individuals with traits best suited to the local environment will survive, mate, and leave behind more, fertile offspring ( with the same ‘fit’ genes)-Differential reproductive success is