1.4 What is Biology? I. The Study of Life A. Many Branches 1. Biochemistry – the chemistry of life

2. Ecology – how organisms interact with each 2. Ecology – how organisms interact with each other & their environment

3. Cell Theory – life on the cellular level

4. Genetics – how organisms pass traits to their offspring

5. Evolutionary Theory - Changes in types of organisms over time

6. Microbiology – study of microscopic organisms

7. Botany – Study of plants

8. Zoology – Study of animals

9. Physiology – Study of the human body

II. Properties of Life A. Cellular Organization 1. cell- smallest unit capable of life 2. cell membrane – thin covering 3. Basic structure same for all organisms B. Homeostasis 1. stable internal conditions a. ex.- body temp. 1. 98.6 oF

C. Metabolism 1. the sum of all the chemical reaction in an organism D. Responsiveness 1. Living things need to respond to environment a. ex. – plants bend toward sunlight E. Reproduction 1. essential part of life b/c nothing lives forever F. Heredity 1. the reason offspring look similar to parents G. Growth 1. Development – organisms grow & change 2. Refers to single individual