Studying Life Section 1-3

1. Studying LifeSection 1-3 Identify characteristics of living things. Explain how life can be studied at different levels.

2. Brainstorm Characteristics of Living Things • Made up of cells • Reproduce • Grow and develop • Obtain and use materials and energy • Respond to stimuli (or environment) • Maintain a stable internal environment (homeostasis) • As a group, change over time (evolve) • Based on a universal genetic code

3. 1. Made Up of Cells • Describe a cell. • Def: Living matter enclosed in a barrier that separates it from its surroundings • The smallest units of an organism that can be considered to be alive! • What characteristics of life do cells exhibit?

4. 2. Reproduction • 2 types: • Sexual reproduction – cells from 2 different parents unite to form the first cell of a new organism (example?) • Asexual (“a” = “not”) – single parent (example?) • Which type do you think is most common?

5. 3. Grow and Develop • Define “growth”. • What is the difference between “growth” and “development”? • Do all organisms exhibit BOTH? • Can nonliving things exhibit growth and development? • You are actually at one of the biggest development stages in your life. • When does growth and development stop?

6. 4. Obtain and Use Materials and Energy • What is the purpose of this? • It is like building a house with materials gathered and energy used. (And there are always waste products left over!) • Organisms gather materials, break them down and make new materials through chemical processes. The combination of all these processes is called metabolism. • So where do we get these materials and energy?

7. 5. Respond to Stimuli (or Environment) • Stimulus:a signal to which an organism responds (examples?)

8. 6. Maintain a Stable Internal Environment (Homeostasis) • Examples: temperature, respiratory rate

9. 7. As a Group, Change Over Time (Evolve) • What do we mean when someone says you’ve adapted to your new situation (i.e., city, school, teacher, break-up)? • How can a plant become adapted to changing environmental conditions? • In biological terms, “adaptation” is a long-term process of change. Individuals don’t adapt; a group of organisms changes over time. • How does this type of adaptation occur?

10. 8. Based on a Universal Genetic Code • Back to reproduction – organisms inherit DNA from their parent(s), which can cause different traits to be passed along. “Only the strong survive” 

11. Branches of Biology • 2 main categories: • Theoretical science • Build on the science knowledge base • Examples: microbiologists, botanists, paleontologists, ecologists • Applied or Practical science • USE the knowledge of theoretical science to improve life • Examples: physicians, medical researchers, wildlife managers, foresters

12. Levels of Organization • Molecular – groups of atoms (water, DNA, proteins, etc) • Cells – plant, nerve, bacteria • Groups of cells – tissues, organs • Organism – individual living thing • Population – group of organisms of ONE TYPE that live in the same area • Community – all populations that live together in the same area • Ecosystem – a community and its nonliving surroundings • Biosphere – the part of Earth that contains all ecosystems