N biology is the scientific study of living things. N most living organisms: consist of organized cells, contain genetic information, use genetic information to reproduce, grow and develop, convert and use energy from the environment, adapt to environmental change, maintain homeostasis. N some organisms are unicellular (one-celled) while others are multicellular. N antony van leeuwenhoek discovered single-celled organisms, and robert hooke concluded that plant tissues were made up of repeated units called cells. N matthew schleiden and theodor schwann stated the cell theory: cells are the basic structural and physiological units of all living organisms, cells are both distinct entities and building blocks of more complex organisms. N spontaneous generation j an old doctrine that life emerged from self-assembly of non- living things (such as maggots from dead meat) Louis pasteur disproved this j life must be present in order for new life to form. N evolution j any genetic or resulting phenotypical change from generation to generation.