Presentation on theme: "An Introduction to Life. Objectives: Explain the basic characteristics shared by all living things. Identify the levels of organization found in living."— Presentation transcript:
Objectives: Explain the basic characteristics shared by all living things. Identify the levels of organization found in living organisms. Explain the system of classification used for living organisms.
All Living Things: Acquire Materials and Energy Metabolism is the sum of all the chemical reactions in an organism During metabolism an organism will build up molecules or break them down Energy is needed to carry on all life functions
All Living Things: Acquire Materials and Energy Source of most energy on Earth: The SUN Plants create nutrients from the sun’s energy during photosynthesis Other organisms consume plants and animals to get their nutrients.
All living things: Maintain an internal balance Homeostasis – attempt by the organism to maintain its internal conditions as the external environment changes Temperature, water, acidity and level of nutrients need to be regulated
All Living Things Respond to their Environment External changes: light, temperature, moisture, gravity Internal changes: sugar levels, salt concentration, carbon dioxide levels, temperature Includes behavior and instinct
All Living Things Reproduce and Develop Asexual reproduction – One parent Sexual reproduction – Two parents
All Living Things Have Adaptations –Modifications that allow them to survive in their environment
All Living Things Have Adaptations Modified over time by natural selection Preserves genetic changes Makes them better suited for their environment.
All Living Things Have Adaptations Evolution is descent with modification, driven by natural selection One species can be an ancestor to many species Explains diversity and unity
All Living Organisms Have Nucleic Acids to control activities –DNA (deoxyribonucleic acid) or –RNA (ribonucleic acid) –Contain instructions for the cell –Carry hereditary information to next generation
Organizing Life Because living things are diverse, taxonomy was created to group organisms into categories and to understand their evolutionary relationships. Least inclusive Most inclusive Domain Kingdom Phylum Class Order Family Genus Species
Organizing Life - Domains Three domains: –Archaea –Bacteria –Eukarya Based on Cell Structure and Function –Prokaryotic cells do not have a true nucleus –Eukaryotic cells have a membrane around their nucleus
Organizing Life - Domains Archaea and Bacteria are both comprised of prokaryotic bacteria. Archaea bacteria live in extreme environments. –Anoxic (no oxygen) –High salinity –High temperature Bacteria Domain includes most pathogenic bacteria
Organizing Life - Domains Eukarya consists of all non-bacterial organisms. Eukarya is divided into four kingdoms. –Protista –Fungi –Plantae –Animalia
Organizing Life – Scientific Names Unique scientific names are used to identify and classify organisms. The scientific name is called the binomial name and consists of a genus and species. –Peas: Genus = Pisum; species = sativa Pisum sativa –Humans: Genus = Homo; species = sapiens Homo sapiens
Can you: Explain the basic characteristics shared by all living things? Are Organized Acquire Materials and Energy Respond to changes in their environment Reproduce and Develop Have Adaptations Have Nucleic Acids as a way to control activities
Can you: Identify the levels of organization found in living organisms? Atoms Molecules cells tissues organs organ systems complex organism
Can you: Explain the system of classification used for living organisms? Domain Kingdom Phylum Class Order Family Genus Species Largest group Smallest group