BIOL 1F90 Study Guide - Midterm Guide: Homeostasis, Organism, Vitalism
Document Summary
Levels of biological organization: atoms, molecules and macromolecules, cells, tissues, organs, organ systems, organism, species, population, community, ecosystems, biosphere. Atoms: smallest functional units of matter that form all chemical substances, cannot be further broken down into other substances by ordinary chemical or physical means, each specific type of atom is a chemical element, e. g. Structure of the atom: a nucleus that contains protons and neutrons, electrons in a large, empty space around the nucleus, diameter of atom including electrons is ~ 100,000 times the diameter of the atomic nucleus. Orbitals: areas in which the probability of finding an electron is high, each orbital holds 2 electrons. Protons: positive subatomic particles which distinguish one element from another. Atomic number: number of protons in an atom, atoms are electrically neutral, so the atomic number also indicates the number of electrons, useful (cid:272)riteria for orga(cid:374)izi(cid:374)g (cid:272)he(cid:373)i(cid:272)al ele(cid:373)e(cid:374)ts i(cid:374)to (cid:862)the periodi(cid:272) ta(cid:271)le(cid:863)