BIO 100 EXAM 1 SDSU ACTUAL 2025/2026 QUESTIONS AND 100% CORRECT ANSWERS

BIO 100 EXAM 1 SDSU ACTUAL 2025/2026 QUESTIONS AND 100% CORRECT ANSWERS What is Biology? - Answer -study of living organisms. What type of science is bio? - Answer -Natural Science, occurs naturally in nature not man made. Others are math, physics,or geology. Five steps of scientific method? - Answer -1) Observe 2) Hypothesize 3) Make prediction 4) Test 5) Draw a conclusion Observe - Answer -Look for interesting patterns or cause-and-effect relationships Formulate a hypothesis - Answer -Hypothesis: a proposed explanation for observed phenomena Null hypothesis: a hypothesis that states a lack of relationship between two factors; stated as a negative Ex. "Echinacea has no effect on the duration and severity of cold symptoms"Hypothesis must be falsifiable to be scientific Make a prediction - Answer -o "If...Then..." o Must be testable Conduct an experiment - Answer -o An experiment that makes it possible to decisively determine whether a particular hypothesis is correct o Need experimental groups, placebo, control groups, treatment, variables etc. Hypothesis vs Law and Principle - Answer -o Hypothesis: a proposed explanation for observed phenomena o Theory: a hypothesis that has been repeatedly tested and supported o Law (Principle): a theory that has been repeatedly tested and supported Comparative method - Answer -Special case of the scientific method o Ex: Seals are more closely related to dogs than to cats (can't really test anything) o Compares patterns of similarity between seals, dogs, and cats o Cannot be tested with traditional experiments Placebo - Answer -a substance that has no effect, used as a control in testing new drugs Atoms - Answer -Atoms are the subunit of all life including molecules There are 92 naturally occurring atomsConsist of: Nucleus (Protons [+] and Neutrons[0]) Electrons (Negative charge; rotate around nucleus in "shells") 4 atoms of life. make up 95% of all life - Answer -carbon oxygen nitrogen hydrogen (COHN - carbon oxygen hydrogen nitrogen) atomic number - Answer -number of protons in nucleas mass number - Answer -protons plus nuetrons isotope - Answer -same element different mass numbers. same electrons and protons but different numbers of neutrons Isotopes may be stable -- nuclei remain intact. Some isotopes are unstable and emit particles and energy: radioactive isotopes. Radioactive isotopes emit radiation ion - Answer -an atom or molecule with a net electric charge due to the loss or gain of one or more electrons. Ionic bond - Answer -losing or gaining electrons. Example: Na+ + Cl- = NaCl (table salt) Strong bonds for dry solids (salt),