Chapter 1 Notes Biology bios = life logos, ology = study of The study of life Living things (organisms) depend upon other organisms and nonliving things to maintain life.

Characteristics of Living Things Eight Basic Characteristics 1. Made up of cells. 2. Reproduce. 3. Living Things are based on a universal genetic code (DNA) 4. Grow and Develop. 5. Obtain and Use Energy. 6. Respond to their environment. 7. Maintain a stable internal environment. 8. Taken as a group, living things change over time.

1. Made up of Cells All living things have an orderly structure (organization) All are made up of one or more cells - basic unit of structure and function in living things. Some organisms may be single celled called Unicellular. Some may be made up of many cells and called Multicellular

2. Reproduce Reproduction is important for the continuation of individual species. Species – a group of organisms that can interbreed and produce fertile offspring in nature. There are two types of reproduction Sexual Reproduction- requires two cells from separate individuals to unite to produce a new organism. Asexual Reproduction - does not require a cell from another individual organism. (budding, fission or mitosis)

3. Living Things are based on a universal genetic code The ability of offspring to resemble their parents in sexual and asexual reproduction is based on a universal genetic code. Biologists know that the directions for inheritance are carried by a molecule called deoxyribonucleic acid, or DNA. DNA provides all the information to control life processes.

4. All Living Things Grow and Develop Growth –results in an increase in the amount of living material (biomass). Growing from a embryo to an adult. (seed- sapling- oak tree) Development – is a result of the changes that take place during the life of an organism. ( caterpillar, pupa, butterfly) (crawl, walk, run)

5. Obtain and Use Energy Energy is used to maintain life - grow, develop and reproduce. Plants and plant-like organisms obtain their energy from sunlight to make food in a process called Photosynthesis. Other organisms obtain their energy from food they eat.

6.Adjust to changes in their Environment (surroundings) Stimulus-anything in the environment that causes an organism to react. (light, temperature, odor, sound, gravity, water & pressure). Response - Reaction to a stimulus, can be slow or rapid, depends on stimulus. Irritability- The ability of an organism to react to stimuli and survive. (structure, behavior, or internal process) - Adaptation

7. Maintain a stable internal environment. Living things maintain a stable internal environment by a process known as homeostasis

8. Living things change over time. Through evolution living things change over time. A gradual accumulation of adaptations over time. A process by which modern organisms have descended from ancient organism.