Molecular and Cellular Biology Exam Questions With Correct Answers

Molecular and Cellular Biology Exam Questions With Correct Answers Biology is the scientific study of____ - answerLife All living things and other matter are composed of ______ (tiny particles consisting of neutrons, protons, and electrons) - answerAtoms Molecular and cellular biology is the study of the molecules and cells that we find in life forms. Which of the following choices is correctly arranged from greatest to smallest? - answerCells, molecules, organelles, atoms Organelles, cells, molecules, atoms Atoms, organelles, cells, molecules Atoms, molecules, organelles, cells Hydrogen atoms always have 1 proton, giving them an atomic number of 1. However, hydrogen atoms can have 0, 1, or 2 neutrons. An atom with the same number of protons but a different number of neutrons is a different _______ of the same atom. - answerIsotope While any given element always has the same atomic number, different isotopes of that element can cause it to have a different atomic _______, which is the sum of neutrons and protons in the atom. - answerMass The _______ table describes all of the known elements with their name, symbol, atomic number, and atomic mass. - answerPeriodic Electrons orbit around the nucleus of an atom in complex patterns called shells. The first (innermost) shell can contain two electrons. Each subsequent shell can hold up to _______ electrons. - answerEight A(n) _______ bond is one in which two atoms share electrons, such as when two hydrogen atoms share their electrons with each other in order to fill their electron shell with two electrons, thus bonding the two atoms to each other. - answerCovalent A(n) _______ bond is one in which one atom transfers one electron to another, resulting in a positive charge for the atom that lost the electron and a negative charge for the atom that gained BRIGHTSTARS EXAM STUDY SOLUTIONS 8/15/2024 2:05 PM the electron. This positive and negative charge creates an electromagnetic attraction that pulls the two atoms together. - answerIonic Some atoms exert more "pull" than others on the the electrons of surrounding atoms. This force is called _______ and can attract electrons or even strip them away from other atoms, as is the case in an ionic bond. - answerElectronegativitiy In a covalent bond between atoms of equal electronegativities, the electrons will be shared equally and no partial positive or negative charges will result. However, in a covalent bond between atoms of widely different electronegativities (such as water), the partial positive and negative charges on opposite sides of the molecule cause this to be called a(n) _______ covalent bond. - answerPolar The partial positive and negative charge (d+ and d-) in a molecule with polar covalent bonds can actually create a weak electromagnetic attraction that bonds other polar molecules together. This type of bond is called a(n) _______ bond. - answerHydrogen Which of the following would have NONPOLAR covalent bonds? - answerH2 and O2 are nonpolar because each atom has an equal electronegativity, so the electron spends equal amount of time on both sides, creating no partial positive or negative charge on one side or the other. There are four main elements that are important for the study of biology, because they make up approximately 96% of all living things. These important elements are: - answerCarbon, hydrogen, nitrogen, and oxygen are called living, or organic compounds. These elements are found everywhere--from fingernails to table sugar. In a chemical reaction, reactants interact with each other and recombine to form _______. This occurs when molecules collide with each other with enough force to split the covalent bonds and reorganize. - answerProducts Chemical reactions in which molecules are broken down into smaller parts and energy is released are called _______ reactions. - answerDecomposition Chemical reactions in which smaller molecules are joined together to form bigger molecules are called _______ reactions - answerSynthesis Water is one of the most important biological compounds, essential to life. The hydrogen bonds that constantly form between water molecules cause water to stick to itself. This property, called _______, causes water to be more structured than other liquids. - answerCohesion The polarity of water molecules not only causes them to stick to each other, it also causes them to stick to any polar sections of other molecules. This property is called _______. - answerAdhesion BRIGHTSTARS EXAM STUDY SOLUTIONS 8/15/2024 2:05 PM Cohesion gives water a higher _______ _______ than most other liquids, which allows insects to walk on the surface of water, or a glas