Studying Life Biology is the study of life! – Sub specialties could include botany, paleontology, marine biology, … – All living things MUST be able to reproduce and produce (convert) energy! They all share these other 3 characteristics to varying degrees – Cell is the basic unit of life – Genetic code is conserved (same) between species – Respond to environment » Maintain homeostasis or maintain a stable internal environment » Exhibit Evolution or change over time

Systems Approach to Biology Each system is part of a larger system. – Atoms make up Molecules – Molecules make up Cells (basic unit of life) – Cells make up Tissues (a group of cells serving a particular purpose) – Tissues make up organs (group of organs working together) – Organs make up the organism (multi-cellular) – A group of similar organisms make up a population (of the same species… can reproduce) – Groups of populations make up a community (interacting or affecting each other) – The community and its non-living surrounding make up the ecosystem – All living things on the Earth form the biosphere

Studying Biology Microscopes… study objects too small to be seen with the “naked” eye – Light … uses lenses and light to view object Can see objects as small as bacteria – Electron… coats object with a reflective surface to bounce electrons off of it producing a 3D image Can see cell surfaces and organelles – Cell culture… creating a cell line from an individual cell for study – Cell fractionation… splitting cells to study the contents Broken cells are spun in a centrifuge to separate parts based on mass