bio 1301: 1.3 Biologists investigate life through experiments that test hypothesis

observation is a tool, but what do we need to do to the information observed?

quantify it (with statistics…)

5 steps of the investigative approach

making observations, asking questions, forming hypothesis, make predictions, testing

two general types of experiments

controlled and comparative

difference between comparative and controlled experiments

cannot control all variables in a comparative experiment; simply gathering and comparing data from different sample groups

what does a statistical test start with 

a null hypothesis

why can you do tests on different species and apply it to others

bc life comes from a common ancestor and is related through chemical composition and molecular behaviors blah blah blah

comparative experiment

compare data gathered from different populations that differ in multiple unknown ways 

controlled experiments

manipulate one factor of interest while holding other variables constant as a means of testing the influence of the manipulated variable

deductive logic

starts with a statement believed to be true and then predict what must also be true

inductive logic

taking observations or facts and formulating a new proposition that is compatable

model systems

small group of species that are subject of extensive research

null hypothesis

the premise that any differences observed in an experiment are simply the result of random differences