Ib 100 Lesson 1
Lesson 1 - Introduction to Biology and Scientific Investigation
The study of the living world.
Modern biology encompasses all levels of organization and interaction:
• among organic molecules
• among organelles within a cell
• among cells in an organ
• among the organ systems in an organism
• between organisms and the abiotic environment
• among individuals in a population
• among species in a biological community
Knowing the facts of biology without an understanding of the relationships among these levels of organization is insufficient to understand the biological world.
How do I know that you are alive?
Life is defined in terms of qualities that the living uniquely share:
• Life is organized o in sequences of increasing complexity (structures within structures) o the basic unit of life is the cell o levels of biological organization are hierarchical from cells - organisms - communities - biosphere
• Life requires energy o the natural tendency of matter is towards disorder (i.e., entropy or randomness) o living systems acquire and use energy to maintain their highly organized state o metabolism: the biochemical reactions that acquire and use energy
• Living things must maintain an internal constancy o this requires a separation from the non-living world o for metabolic processes to function normally, living things need to keep themselves stable in temperature, moisture level, chemistry, etc. o homeostasis: the ability to maintain internal constancy (i.e., to stay the same)
• Living things grow, develop, and reproduce o vital if a population of organisms is to survive more than one generation> o "Instructions" for growth and development are encoded in genes
• Living things react to environmental change - Irritibility - (an individual reacts to its environment) o reaction may be immediate as in a reaction to extreme heat, or longer term as in a change in leaf color in response to day length, but certainly within the lifetime of the
The study of the living world.
Modern biology encompasses all levels of organization and interaction:
• among organic molecules
• among organelles within a cell
• among cells in an organ
• among the organ systems in an organism
• between organisms and the abiotic environment
• among individuals in a population
• among species in a biological community
Knowing the facts of biology without an understanding of the relationships among these levels of organization is insufficient to understand the biological world.
How do I know that you are alive?
Life is defined in terms of qualities that the living uniquely share:
• Life is organized o in sequences of increasing complexity (structures within structures) o the basic unit of life is the cell o levels of biological organization are hierarchical from cells - organisms - communities - biosphere
• Life requires energy o the natural tendency of matter is towards disorder (i.e., entropy or randomness) o living systems acquire and use energy to maintain their highly organized state o metabolism: the biochemical reactions that acquire and use energy
• Living things must maintain an internal constancy o this requires a separation from the non-living world o for metabolic processes to function normally, living things need to keep themselves stable in temperature, moisture level, chemistry, etc. o homeostasis: the ability to maintain internal constancy (i.e., to stay the same)
• Living things grow, develop, and reproduce o vital if a population of organisms is to survive more than one generation> o "Instructions" for growth and development are encoded in genes
• Living things react to environmental change - Irritibility - (an individual reacts to its environment) o reaction may be immediate as in a reaction to extreme heat, or longer term as in a change in leaf color in response to day length, but certainly within the lifetime of the