BIOLOGY CHAPTER 1 THE PROPERTIES OF LIFE 1 Order all living things exhibit complex but ordered organization 2 Regulation the environment outside an organism may change but the organism can adjust its internal environment keeping it within appropriate limits 3 Growth and development information carried by DNA controls the pattern of growth and development in all organisms 4 Energy processing organisms take in energy and use it to perform all of life s activities they emit it as heat 5 Response to the environment all organisms respond to environmental stimuli 6 Reproduction organisms reproduce their own kind 7 Evolution reproduction underlies the capacity of populations change over time The biosphere consists of all environments on earth Emergent properties result from the arrangement and interaction of parts within a system They emerge as complexity increases SCOPE OF LIFE 1 Biosphere includes all life and all the places where life exists 2 Ecosystems consists of all living organisms in a particular area and all the nonliving components of the environments with which life interacts such as soil water and light 3 Communities all organisms in the tide pool are collectively called a community 4 Populations within communities are various populations groups of interacting individuals of one species 5 Organisms an individual living thing 6 Organ systems and organs an organism s body consists of several organ systems each of which contains two or more organs 7 Tissues each organ is made up of several different tissues such as the heart muscle A tissue consists of a group of similar cells performing a specific function 8 Cells the cell is the smallest unit that can display all the characteristics of life 9 Organelles functional components of cells such as the nucleus that houses the DNA 10 Molecules and Atoms molecules are clusters of even smaller chemical units called atoms Each cell consists of an enormous number of chemicals that function together to give the cell the properties we recognize as life ECOSYTEMS All living organisms in a specific area along with all the nonliving factors with which they interact form an ecosystem Dynamics of any ecosystem depend on two main processes 1 recycling of chemical nutrients minerals that plants absorb from the soil can eventually be recycled to the soil by microorganisms that decompose leaf litter and other organic refuse Most ecosystems have 3 modes of nutrition a producers are photosynthetic organisms such as plants consumers are the organisms such as animals that feed on the plants decomposers such as fungi and many bacteria break down waste products and the remains of deceased organisms changing complex dead material into simple nutrients that are recycled The action of decomposers ensures that nutrients are recycled within an ecosystem 2 flow of energy energy doesn t get recycled ecosystem gains and loses energy constantly Most ecosystems are solar powered Energy that enters an ecosystem as sunlight is captured by producers when plants and other photosynthesizers absorb the sun s energy and convert it to the chemical energy of sugars and other complex molecules Chemical energy is then passed through a series of consumers and eventually decomposers powering each organism in turn Some energy is converted to heat which is then lost from the system Thus energy flows through an ecosystem entering as light and exiting as heat CELLS AND THEIR DNA The cell is the level at which properties of life emerge the lowest level of structure that can perform all activities required for life Every cell is enclosed by a membrane and use DNA as their genetic information The membrane regulates the passage of materials between the cell and its surroundings Two cell types 1 prokaryotic very simple and small no nucleus but still contains DNA cells of bacteria are prokaryotic 2 Eukaryotic contains nucleus includes plants and animals subdivided by internal membranes into different functional compartments called organelles All cells use DNA as the chemical material of genes units of inheritance that transmit information from parent to offspring Genome the entire book of genetic instructions that an organism inherits THE THREE DOMAINS OF LIFE 3 domains bacteria archaea and eukarya Bacteria and archaea have prokaryotic cells Eukarya all have eukaryotic cells which included three kingdoms plantae fungi and animalia The kingdoms are distinguished partly by how the organisms obtain food Plants produce their own sugars and foods Fungi are mostly decomposers obtaining food by digesting dead organisms and wastes Animals obtain food by ingesting and digesting other organisms Protists are eukaryotes that do not fit into any of the three kingdoms EVOLUTION Evolution is the process of change that has transformed life on earth Evolution is the fundamental principle of life and the theme that unifies all of biology Organisms living on earth are modified descendants of common ancestors
View Full Document
Unlocking...