Biology Final Exam Practice| 83 questions| with complete solutions

Which of the following statements correctly summarizes cell theory? correct answer: All organisms are made of cells, and all cells come from preexisting cells. Natural Selection correct answer: Natural selection occurs when heritable variation in certain traits leads to improved success in reproduction. Natural selection acts on individuals. Which statement best explains the physical basis for why oil (molecules containing only carbon and hydrogen) and water do not mix? correct answer: Oils are nonpolar molecules that cannot interact with water molecules via hydrogen bonding. Because oils are neither polar nor charged, they cannot interact with the partial charges on water molecules. What type of energy is stored in the chemical bonds of a molecule? correct answer: Potential Energy Based on position Which functional group is least polar? correct answer: Sulfhydryl The electronegativity of sulfur (S) is only slightly higher than that of hydrogen (H) How are nucleotides linked together to form a polynucleotide chain? correct answer: In DNA and R