CH 1 Introduction to Biology.pdf

Introduction to Biology Biology is the scientific study of life. The properties/characteristics found among all living organisms. How we define life. Property/Characteristics Explanation 1. Order...

Introduction to Biology Biology is the scientific study of life. The properties/characteristics found among all living organisms. How we define life. Property/Characteristics Explanation 1. Order Life is characterized by highly ordered structures from simple cells to entire ecosystems. 2. Reproduction The ability of organisms to reproduce their own kind. 3. Growth & Development Consistent growth and development controlled by inherited DNA. 4. Response to the An ability to respond to environmental stimuli. environment. 5. Energy processing The use of chemical energy to power an organism’s activities and chemical reactions. 6. Regulation Maintain homoeostasis: an ability to control an organism’s internal environment within limits that sustain life. 7. Evolutionary adaptation Adaptations evolve over many generations, as individuals with traits best suited to their environments have greater reproductive success and pass their traits to offspring. The diversity of life. The Three Domain classification system. Diversity is the hallmark of life. The diversity of organisms on earth have been classified and named by taxonomists. Taxonomy is the branch of biology that classifies organisms within the Domains and names them. The scientific naming of life uses binomial nomenclature. A two-naming system based upon the genus species classification of organisms. Human is our common name; our scientific name is Homo sapiens. We belong to genus Homo, species sapiens. Note the first letter in the genus name is capitalized. The entire name is italicized. The Three Domains Domains are categorized by cell type. Prokaryotic Cells Eukaryotic Cells Found only in unicellular (1 cell) organisms. Found in unicellular and multicellular organism. Small Commonly larger than prokaryotic cells. Simple – Lack internal parts (membrane bound Complex – Contain membrane enclosed organelles) organelles (structure/function). Domain Bacteria Domain Eukarya Domain Archaea Domain Bacteria: The most abundant and diverse organisms on the planet. Currently divided into five groups. Rapidly adapt to changing environments. Affect health and cause disease. Help clean up the environment. Have unparalleled nutritional diversity. Domain Archaea: Prokaryotic organisms that live in EXTREME environments Extreme halophiles-love salt (dead sea, great salt lakes). Extreme thermophiles –love heat or acidic environments (deep ocean vents, acidic pools). Methanogens-don’t need oxygen (MSW landfills).  Domain Eukarya: Eukaryotic Organisms (with complex cells) divided into 4 Kingdoms. Kingdoms: Kingdom Protista (unicellular) Kingdom Plantae Kingdom Fungi (multicellular) Kingdom Animalia Classification rank: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species Hierarchy of life. Beginning with the simplest/smallest (invisible to the unaided eye) to the most complex (visualized from outer space). From the simplest… Atom The smallest units of matter that retain the properties of elements. Molecules A combination of two or more atoms held together by chemical bonds. Organelles The internal machinery of cells. Cells The fundamental unit of all life. Where the properties/characteristics of life emerge. Tissues A collection of cells that function together. Organs A collection of tissues that function together. Organ System A collection of organs that function together. Organism Encompasses all organ systems working together. Population A group of organisms of the same species that interact and interbreed. Community An assemblage of different populations with an area that are interacting. Ecosystem Includes the community and the physical features within a given area. Landscape A collection of interconnected ecosystems. Biosphere All of Earth where life exists. Most complex. The unifying themes of biology. Evolution Is the process of change. Biological evolution is defined as decent with modification. An editing process, NOT a creative or goal driven process. Organisms do NOT evolve, a population evolves as they experience new circumstance. Natural Selection is the mechanism of evolution. How populations change over time. Evolutionary Trees Darwin suggests that over many generations (thousands-millions of years) natural selection could lead to major alterations of species. Flow of information Genetic information DNA encodes for organism structure and function. Gene expression is the process of DNA information being transcribed into RNA which is then translated to protein. Proteins are involved in nearly all structure and function at the cellular level.  Structure & function The relationship between structure and function can be observed at every level of life. At the molecular level, the structure of a protein correlates with its function. For example, hemoglobin molecules transport oxygen in blood. On the cellular level, the shape/structure of the cell correlates with its function. For example, long extensions of nerve cells (neurons)enable them to transmit impulses from your spinal cord to your toes. Transfer and transformation of matter and energy. Energy flows through an ecosystem in one direction. entering as sunlight Converted to chemical energy by producers/autotrophs Plants are photoautotrophs that convers solar energy into chemical energy by the process of photosynthesis. Passed on to consumers/heterotrophs Omnivores (plant/meat eaters) consume matter which is transferred into biomass and converted into energy via cellular respiration. Decomposers break down organic material which is transferred into biomass and converted into energy via cellular respiration. With each transfer and transformation of matter energy is lost, exiting as heat.  Interactions within and between systems. Using an approach called systems biology, scientists attempt to model the behavior of biological systems by analyzing the interactions among their parts. This comes back to understand the complexity of life in the biosphere. Examples: 1. The communication among the body The respiratory system and the organs within an organism. circulatory system work closely together to deliver oxygen to cells and to get rid of the carbon dioxide the cells produce. 2. The interaction between males and Breeding behavior and courtship females in a population. rituals. 3. The interaction between living Interactions between organisms: organisms within ecosystems. Predator – Prey, Competition, Parasitism. 4. The interaction between and within The amount of water, light different ecosystems. conditions, habitat fragmentation.