Characteristics of Life

1. Characteristics of Life

2. Biology • = study of living things • There is great diversity among living things • All living things share certain characteristics

3. Cells • All living things are made of cells • Cell = smallest unit of structure and function for living things • Some organisms are • Unicellular = made up of one cell • Multicellular = made up of many cells

4. Reproduction • All living things are able to produce offspring • Through this process, living things pass on their genetic traits

5. Genetic Code • All living things have a universal genetic code • The genetic code is based on DNA and its four nitrogen bases – A, T, C, and G

6. Growth / Development • All living things grow / develop at some point during their lifetime. • Growth = increase in size; usually occurs through mitosis (cell division) • Development = changes; for instance, specialization of certain structures for certain jobs in an organism’s body

7. Metabolism • All living things must obtain and use energy • Metabolism = all of the reactions in an organism • Photosynthesis = process plants use to get energy from the sun • Cellular respiration = process used to break down food energy into cell energy (ATP)

8. Respond to Environment • All living things are able to respond to things happening in and around them (stimuli) • Plants grow toward sunlight • People shiver when they are cold

9. Homeostasis • All living things try to maintain a stable internal environment • Resting heart rate = 72-76 beats per minute • Resting breathing rate = approx. 15 breaths per minute • Normal body temperature = 98.6 oF (37 oC)

10. Evolution • = change in a species over time • All living things, as a group, change over time • Populations evolve • Population = members of the same species living in the same place at the same time • Individuals do NOT evolve