The Science of Life--Biology--

1. The Science of Life--Biology-- • -the study of life or living things • -from Latin BIOS; meaning “life” • and LOGOS; meaning “to study” • -Why use Latin? • -because it is a “dead” language • -nobody uses Latin as their native language • -if nobody uses it, it doesn’t ever change from “slang” or common usage changes

2. -What does it mean to be “alive”? • (student responses--back to 1995 classes) • -breathing • moving • growth • need nutrition • respond to stimuli from environment • reproduce. • -heal, think, pulse, • (added in ‘96)

3. -Characteristics of Life • -All living things exhibit the following: • 1- highly organized & contain many complex substances • 2- made up of one, or more, cells • cell theory states • cell is the basic unit of structure and function • all cells come from pre-existing cells • 3- use energy

4. 4- definite form & limited size • 5- limited life span • 6- growth • 7- respond to changes in the environment • 8- reproduce • 9- groups of living things evolve over time (meaning they change)

5. The Life Processes • -functions an organism performs in order to stay alive • 1- Nutrition-take materials from the environment, change it into a form it can use

6. The Life Processes (cont.) • two methods of obtaining nutrition • -autotrophic-produces its own food from simple things • eg-plants photosynthesize from sunlight, CO2 &H2O • -heterotrophic-obtain food from eating nutrients already in the environment • eg-animals eat plants

7. The Life Processes (cont.) • 2- Transport-substances within the organism are distributed to where they are needed within the organism • 3- Respiration-release of chemical NRG stored in certain nutrients • eg-C6H12O6 (glucose) is broken down into CO2 (carbon dioxide)and H20 (water) and NRG is released

8. The Life Processes (cont.) • 4- Synthesis-combine simple substances to form a complex substance • Assimilation-the use of materials in the body of an organism • 5- Growth-process by which all living organisms increase in size • increase the number of cells • 6- Excretion-removal of waste materials from the organism

9. The Life Processes (cont.) • 7- Regulation-process by which an organism maintains a stable internal environment (homeostasis) • controls functions by sending messages throughout the body • -nervous system (nerves) • -endocrine system (hormones) • responds to changes in the internal and external environment

10. The Life Processes (cont.) • 8- Reproduction-process by which living organisms produce new organisms of their own kind • NOT NECESSARY for the continued life of the individual • IS NECESSARY for the continued life of that type of organism

11. Two Types of Reproduction • 1- asexual-only one parent • all offspring are identical to the parent • 2- sexual-two parents • all offspring have a combination of both parent’s traits

12. The Life Processes (cont.) • 9- Metabolism • all the chemical reactions occurring within a cell (or the cells) of an organism • basically includes all of the above processes together

13. Studying Living Things--Levels of Organization • Molecular Level • Atoms and Molecules make up all living things • Cellular Level • the smallest unit of life carrying out ALL life functions • Tissue Level • A group of cells that performs a specific function in an organism

14. Levels of Organization (cont.) • Organ Level • several types of tissues that function together for a specific purpose • Organ System Level • several organs working together to perform a function

15. Levels of Organization (cont.) • Organism • not all organisms are made up of systems • range from single celled, to tissue, on up to... • all of the organ systems working together to for a complete organism • Population Level • a group of organisms of the same species that lives together in a particular location

16. Levels of Organization (cont.) • Community • Groups of populations living in the same place • Ecosystem • Includes the community of organisms as well as the non-living factors