BIOL 1001 Chapter : Ch 1 Bio 1001
Document Summary
Organisms share common characteristics that, taken together, define life: acquire and use materials and energy, actively maintain organized complexity, sense and respond to stimuli, grow, reproduce, evolve, collectively. Cell: basic unit of life, separated from surroundings by a membrane, encloses a variety of structures and chemicals in a fluid environment, figure 1-1. Multicellular: exists as a collection of at least two cells. Organisms actively maintain organized complexity: living things continuously use energy to maintain themselves, cells pump chemicals in and out, allowing necessary chemical reactions to occur, cells and organisms maintain relatively constant internal conditions, or homeostasis. Organisms grow: every organisms becomes larger over time, plants and animals grow by producing. Mutation can lead to genetic variation among members of a population. Natural selection of traits that allow certain individuals to survive and reproduce better than others in a given environment. Mutations occur when changes in genes are mistakenly copied. Occur in parent sperm or egg cells.
