Biology 121 Test Review ( Chapters 1-5) Actual real exam updated questions and answers 2026 solutions guaranteed.

What domains include prokaryotic cells? - correct answers Bacteria & Archaea What is the most diverse prokaryote? - correct answers Bacteria These live in extreme environments like salty lakes? - correct answers Archaea What is the most diverse single celled eukaryotes? - correct answers Protists What two kingdoms are multicellular eukaryotes ingest food and use photosynthesis as a source of food? - correct answers Kingdom Animalia & Kingdom Plantae What is a hypothesis? - correct answers a testable explantation for an observation What is the process where living things obtain energy from their environment? - correct answers Energy processing What is deductive reasoning? - correct answers establishing a test of hypothesis What is an example of an acid ( low pH #)? - correct answers Lemon juice/vinegar What is an example of a base ( high pH #)? - correct answers Bleach/ammonia What is adhesion? - correct answers Water readily sticks to other substances Their charge is +1 and determines atomic number? - correct answers Protons They have no charge and determines mass number? - correct answers Neutrons Their charge is -1 and they move in an cloud? - correct answers Electrons What is an universal solvent? - correct answers Water How many elements are essential to human biology located at the bottom of the periodic table? - correct answers 25 What is an element? - correct answers It cannot be broken down to other substances by chemical means What is a compound? - correct answers 2 or more elements in a fixed ratio What determines hot spots of metabolic activity? - correct answers PET (Positron-emission tomography) What determines the atomic mass? - correct answers the sum of its protons and neutrons in daltons One in which the nucleus decays spontaneously, giving off particles and energy and is used for dating fossils? - correct answers Radioactive isotopes These interactions usually result in atoms staying close together held by attractions? - correct answers Chemical bonds What is a covalent bond? - correct answers two atoms each with an unpaired electron in its outer shell, actually share a pair of electrons What are atoms held together by covalent bonds? - correct answers Molecule An atoms's attraction for shared electrons? - correct answers Electronegativity The electrons are shared equally between the bonds? - correct answers Non-polar covalent bonds The unequal sharing of electrons produces what? - correct answers Polar covalent bond What is an ion? - correct answers an atom or molecule with an electrical charge resulting from a gain or loss of one or more electrons What is the most important types of weak bonds? - correct answers Hydrogen bond What has an unequal distribution of charges? - correct answers Polar molecule What is the breaking of existing chemical bonds and forming new ones? - correct answers Chemical reactions The conversion of starting materials? - correct answers The reactants The material resulting from the chemical reaction? - correct answers The products What is the tendency of molecules of the same kind to stick together? - correct answers Cohesion What is the clinging of one substance to another? - correct answers Adhesion What is the energy associated with the random movement of atoms and molecules? - correct answers Thermal energy What is the measure of intensity of heat? - correct answers Temperature This occurs because the molecules with the greatest energy leave? - correct answers Evaporative cooling What is a liquid consisting of a uniform mixture of 2 or more substances? - correct answers A solution What are the bond form strongest to weakest? - correct answers Covalent, ionic, and hydrogen bonds What is a solvent? - correct answers a dissolving agent What is a solute? - correct answers substance that is dissolved What is a widely effective solvent? - correct answers Material that is solvent What is an aqueous solution? - correct answers One in which water is the solvent This donates hydrogen ions to solutions? - correct answers Acids A substance that reduces the hydrogen ion concentration of a solution? - correct answers Base What do we use the pH scale for? - correct answers How acidic or basic a solution is What is a buffer? - correct answers substances that minimize changes in pH The CO2 dissolving in seawater lowers the pH of the ocean? - correct answers Ocean acidification Hydrophilic - correct answers molecules that dissolve in water (water loving) Hydrophobic - correct answers molecules that DO NOT dissolve in water Values that are below 7 on the ph scale are said to be - correct answers Acidic= higher hydrogen concentration Values exactly at 7 on the ph scale are? - correct answers Neutral= Concentration are equal Values that are above 7 on the pH scale are said to be - correct answers Basic= higher OH concentration What are the most abundant organic compounds? - correct answers Carbohydrates, lipids, and proteins What do carbohydrates contain? - correct answers Carbon, hydrogen, and oxygen What is the basic unit of carbohydrates and its simple sugar consists of 3 to 6 carbon atoms linked together? - correct answers Monosaccharides (Fructose/Glucose) What is the combination of 2 monosaccharides? - correct answers Disaccharide ( Sucrose) What are several monosaccharides linked together? - correct answers Polysaccharides What is the storage polysaccharide in plants? - correct answers Starch What is the storage polysaccharide in animals? - correct answers Glycogen What is the addition of water molecules while breaking bonds with the assistance of an acid and enzyme? - correct answers Hydrolysis What are polar molecules? - correct answers areas of slightly positive and negative charges unequally sharing electrons What are lipids used for? - correct answers Structure, energy storage, signaling, insulation, and protection What is the most familiar lipid and is also a neutral fat, consists of 3 carbon atoms with a glycerol molecule? - correct answers Triglyceride These are 3 long chains of carbon and hydrogen - correct answers Fatty acids What does non polar mean? - correct answers They do not have any charge at all What is not soluble in water? - correct answers Fats What are large complex molecules composed of amino acids? - correct answers Proteins What are short chains of amino acids? - correct answers Peptides A longer chain of amino acids are known as? - correct answers Polypeptides What is a reducing sugar? - correct answers One that can reduce another compound as part of a redox reaction (Benedict's Reagent) What are lipids? - correct answers Hydrophobic What are saturated fatty acids? - correct answers a fatty acid that has no double bonds in its hydrocarbon chain has the max number of hydrogen atoms attached to each carbon atom What are carbon based molecules and they usually contain hydrogen atoms in addition to the carbon? - correct answers Organic compounds What forms the backbone of most organic molecules? - correct answers Carbon chains What are compounds with the same formula but different structural arrangements? - correct answers Isomers What are compounds only composed of hydrogen and carbon? - correct answers Hydrocarbons What are the first five chemical groups and affect a molecules function by participating in chemical reactions? - correct answers Functional groups What consists of a hydrogen atom bonded to an oxygen atom, which is bonded to the carbon skeleton? - correct answers A Hydroxyl group A carbon atom in linked by a double bond to an oxygen atom - correct answers A carbonyl group If the carbonyl is at the end of the carbon skeleton, what is the compound called? - correct answers Aldehyde If it is within the chain of the skeleton, what is the compound called? - correct answers Ketone This group consists of a carbon double bonded to an oxygen atom and also bonded to a hydroxyl group? - correct answers Carboxyl group What has a nitrogen bonded to two hydrogen and the carbon skeleton? - correct answers Amino group What are the building blocks of proteins? - correct answers Amino acids What consists of a phosphorus atom bonded to 4 oxygen atoms? - correct answers Phosphate group What consists of a carbon bonded to 3 hydrogen atoms and affects the expression of genes? - correct answers A methyl group What are the three classes that make up macromolecules? - correct answers Carbohydrates, proteins, and nucleic acids Cells make most of their macromolecules by joining smaller molecules into chains called? - correct answers Polymer What are the building blocks of polymers? - correct answers Monomers What is the process of when cells link monomers together to form polymers? - correct answers Dehydration reaction These are specialized macromolecules that speed up chemical reactions in cells? - correct answers Enzymes How many amino acids are in proteins? - correct answers 20 kinds of amino acids What are the monomers of carbohydrates? - correct answers Monosaccharides What is a common monosaccharides of central importance in the chemistry of life? - correct answers Glucose What are 3 common types of polysaccharides? - correct answers starch, glycogen, and cellulose What is the most abundant organic compound on Earth? - correct answers Ce