Chapter 1 introduction the scientific study of life. In this chapter, the following content will be discussed: The characteristics of life, humans are related to other animals, science as a process, making sense of a scientific study, science and social responsibility. | Chapter 1 Biology 25: Human Biology Prof. Gonsalves Los Angeles City College Loosely Based on Mader’s Human Biology,7th edition Chapter 1 Introduction: The Scientific Study of Life Biology: The study of life. Greek origin: Bio: Life Logos: Study of I. Life is based on many structural levels Levels of biological organization: Atoms Molecules Subcellular organelles Cells Tissues* Organs* Organ systems* Organism: May consist of a single cell or a complex multicellular organism. * Level of organization not found in all organisms Levels of organization beyond organism: Population: Group of organisms of the same species that interact with one another. Community: Several different populations living together in same area (.: lake, forest, jungle). Ecosystem: Interactions of community with non-living environment (air, water, soil). Ecosphere: All ecosystems on planet earth. Includes: Biosphere: All biological communities on earth. Atmosphere (air) Hydrosphere (water) Lithosphere (crust) Common features of all organisms: 1. Cells: Basic structural and functional unit of life. Genetic information contained in DNA. 2. Growth and Development: Growth: Occurs by an increase in cell size, cell number, or both. Development: Changes that take place during an organism’s life. 3. Energy use and metabolism: All organisms must take in and transform energy to do work, to live. Metabolism: All chemical reactions and energy transformations essential for growth, maintenance, and reproduction. 4. Regulation External environment may change, but internal environment remains fairly constant. Homeostasis: Organisms constantly strive to maintain a “steady state” (.: constant body temperature or blood pH) despite changes in the internal and external environment. Metabolism is regulated by homeostatic mechanisms. 5. Movement: Internal movement: Characteristic of all life. Locomotion: Self-propelled movement from point A to point B. Not observed in all life forms. 6. Respond to environmental | Chapter 1 Biology 25: Human Biology Prof. Gonsalves Los Angeles City College Loosely Based on Mader’s Human Biology,7th edition Chapter 1 Introduction: The Scientific Study of Life Biology: The study of life. Greek origin: Bio: Life Logos: Study of I. Life is based on many structural levels Levels of biological organization: Atoms Molecules Subcellular organelles Cells Tissues* Organs* Organ systems* Organism: May consist of a single cell or a complex multicellular organism. * Level of organization not found in all organisms Levels of organization beyond organism: Population: Group of organisms of the same species that interact with one another. Community: Several different populations living together in same area (.: lake, forest, jungle). Ecosystem: Interactions of community with non-living environment (air, water, soil). Ecosphere: All ecosystems on planet earth. Includes: Biosphere: All biological communities on earth. Atmosphere (air) Hydrosphere (water) Lithosphere (crust) .
