Biology Notes PDF

Atom: the smallest unit of matter that retains all the chemical properties of an element. (NPEs) Molecule: two or more atoms joined together Macromolecules: large molecules that are formed by polymerization (DNA) Organelles: small structures that exist within cells Cell: smallest fundamental...

Atom: the smallest unit of matter that retains all the chemical properties of an element. (NPEs) Molecule: two or more atoms joined together Macromolecules: large molecules that are formed by polymerization (DNA) Organelles: small structures that exist within cells Cell: smallest fundamental unit of structure and function Prokaryotes: single-celled organisms without membrane-bound nucleus Eukaryotes: have membrane-bound organelles and nucleus, single/multi- celled Tissue: groups of similar cells that perform specific functions Organs: collections of tissues grouped together organ system Population: individuals of species living within specific area Community: sum of populations Ecosystem: all living things Biosphere: collection of ecosys There are 8 key characteristics of life: Reproduction Heredity Cellular Organization Growth and development Adaptation through evolution Response to stimuli Homeostasis metabolism Reproduction For something to be considered alive, it must be able to reproduce and create offspring. Single-celled organisms reproduce by duplicating DNA, dividing and creating new cells Genes are units of information with an individual’s DNA that are passed to offspring during reproduction. Growth Development All organisms develop over time to become more physically/mentally mature. Organisms grow/develop following instructions coded for by genes Heredity The ability to pass on genetic material (DNA) from parent to offspring Phenotypic traits (physical appearance) vs genotypic traits (genetic code) Cellular Organization/Order: Organisms are highly organized and coordinated structures that consist of one or more cells Simple, single-celled organisms to multicellular organisms Sensitivity/Response to Stimuli: Organisms respond to diverse stimuli within their environment (plants) Movement of organisms makes up a large part of its behavior – behavior is directed toward avoiding injury, acquiring food or mating. Adaptation through evolution: All living things have evolved throughout time, and will continue to adapt to an ever-changing environment (personal exp.) Individuals better adapted to their environment tend to produce more offspring. Natural selection is the differential reproductive success of adapted individuals. Results in changes of characteristics of a population over time. Evolution is the change in frequency of traits in populations and species over time. Homeostasis The ability of organism to maintain stable internal conditions when faced with varying factors as they change from one moment to next (temperatures, pH, water balance within cells etc.) Metabolism/Energy Processing All organisms use sources of energy for metabolic activities Organisms capture energy from sun and convert to chemical energy (photosynthesis) or they use chemical energy in molecules they take in as food (cellular respiration)