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12 | | A covalent bond is characterized by |
| | A) | sharing electrons by the atoms |
| | B) | sharing electrons by one atom and gaining electrons by the other |
| | C) | the attractive force between oppositely charged atoms |
| | D) | involvement of too many different forces |
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13 | | At present how many elements are known? |
| | A) | 32 |
| | B) | 125 |
| | C) | 500 |
| | D) | 108 |
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14 | | Which of the following best describes a proton? |
| | A) | A proton has one positive charge, mass of one unit and found in nucleus. |
| | B) | A proton has negative charge, mass of one unit and found in nucleus. |
| | C) | A proton has one negative charge, no mass and found in nucleus. |
| | D) | A proton can have both positive and negative charge and found in nucleus. |
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15 | | When an atom is electrically charged (either positive or negative), it is known as a(n) |
| | A) | molecule |
| | B) | radiation |
| | C) | ion |
| | D) | element |
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16 | | In ionic bonding |
| | A) | only non-polar molecules are involved |
| | B) | a "sea of electrons" is formed |
| | C) | electrons are transferred from one atom to another |
| | D) | two hydrogen atoms share one pair of electrons |
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17 | | Peptide bonds are found in all the molecules of |
| | A) | carbohydrates |
| | B) | organic compounds |
| | C) | lipids |
| | D) | proteins |
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18 | | The four most abundant elements in the human body are |
| | A) | carbon, hydrogen, oxygen, and iron |
| | B) | carbon, hydrogen, oxygen, and nitrogen |
| | C) | calcium, hydrogen, sodium, and potassium |
| | D) | carbon, oxygen, magnesium, and zinc |
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19 | | The hydrogen and oxygen atoms in a molecule of water are held together by a(an) __________ bond. |
| | A) | polar covalent |
| | B) | ionic |
| | C) | peptide |
| | D) | hydrogen |
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20 | | Which statement about hydrogen bonding is true? |
| | A) | Hydrogen bond is formed by sharing electrons between atoms. |
| | B) | Hydrogen bond also requires formation of ions. |
| | C) | Hydrogen bond is a weak force between atoms in a molecule but is of enormous importance in physiology. |
| | D) | Hydrogen bond is nothing but a different form of hydrogen ion. |
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21 | | Bonding is necessary for the formation of |
| | A) | molecules |
| | B) | ionic radiation |
| | C) | elements |
| | D) | atoms |
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22 | | A molecule is said to be _______ when it gains one or more electrons. |
| | A) | a free radical |
| | B) | electrified |
| | C) | oxydized |
| | D) | reduced |
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23 | | When two atoms are held together because their valence electrons orbit around both of them, they are united by a(n) ________ bond. |
| | A) | ionic |
| | B) | hydrogen |
| | C) | covalent |
| | D) | electron |
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24 | | The complex and unique three-dimensional structure of a protein molecule is maintained largely by __________ bonds. |
| | A) | electrovalent |
| | B) | covalent |
| | C) | ionic |
| | D) | hydrogen |
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25 | | The molecular formula C6H12O6 means it has the following constituents |
| | A) | one hydrogen and two oxygen atoms |
| | B) | one carbon, one hydrogen and one oxygen atoms |
| | C) | six carbon, twelve hydrogen and six oxygen atoms |
| | D) | one carbon, two hydrogen and one oxygen atoms |
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26 | | When molecules are formed by sharing electrons equally, those molecules are called |
| | A) | salt molecules |
| | B) | polar covalent |
| | C) | non-polar covalent |
| | D) | macromolecules |
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27 | | Which of the following statements about molecules is true? |
| | A) | When two or more atoms bond, they form a new structure called a molecule. |
| | B) | Molecules have to be formed by atoms of same type of elements. |
| | C) | Molecules have to be formed by atoms of different type of elements. |
| | D) | All of the above statements are false. |
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28 | | Which one among the following expresses the chemical formula of glucose? |
| | A) | C6H6O6 |
| | B) | C6H12O6 |
| | C) | CO2H2O |
| | D) | C6H12O6 |
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29 | | Small molecules combine to form |
| | A) | atoms |
| | B) | atomic molecules |
| | C) | macromolecules |
| | D) | micromolecules |
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30 | | An example of macromolecules in our body includes |
| | A) | nucleic acids |
| | B) | proteins |
| | C) | carbohydrates and lipids |
| | D) | all of the above |
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31 | | If there are two lines connecting the atoms in any molecule, those double lines represent a(an) |
| | A) | single bond |
| | B) | double bond |
| | C) | ionic bond |
| | D) | no relation |
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32 | | Which statement about solubility of a compound is TRUE? |
| | A) | Compounds are always solid and cannot be dissolved in any solution. |
| | B) | Solubility properties of compounds are completely unknown. |
| | C) | Compounds are always liquid and can be dissolved in any solution. |
| | D) | Compounds, depending on their structure, could be water-soluble or fat-soluble. |
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33 | | Tissues can suffer extensive damage from ________________, due to the lack of antioxidants in the body. |
| | A) | free radicals |
| | B) | free electrolytes |
| | C) | free energy |
| | D) | a pH imbalance |
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34 | | A(n) _______ reaction is one in which two or more smaller molecules with low free energy are combined into a larger molecule with greater free energy. |
| | A) | endergonic |
| | B) | exergonic |
| | C) | synthesis |
| | D) | decomposition |
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35 | | An oxidizing agent _______ the molecule it oxidizes. |
| | A) | increases the size of |
| | B) | adds H or H2 to |
| | C) | adds electrons to |
| | D) | reduces the free energy of |
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36 | | A reduction reaction is always accompanied by |
| | A) | an oxidation reaction |
| | B) | decomposition |
| | C) | some energy release |
| | D) | huge nuclear decay |
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37 | | Which of the following is a synthesis reaction? |
| | A) | Two amino acids are bonded together to form a dipeptide. |
| | B) | Sucrose is chemically broken down to form one molecule of glucose and one molecule of fructose. |
| | C) | Sodium chloride is dissolved in water. |
| | D) | Several dipeptide chains are formed from digestion of a long polypeptide chain. |
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38 | | Physical and chemical changes occurring in the body are defined as |
| | A) | metabolism. |
| | B) | a synthesis reaction. |
| | C) | a decomposition reaction. |
| | D) | digestion. |
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61 | | Which one among the following has a major role in our body structure? |
| | A) | calcium carbonate |
| | B) | sodium chloride |
| | C) | magnesium sulfate |
| | D) | all of the above |
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62 | | When a solute is dissolved in any solvent, the resulting mixture is called |
| | A) | a(n) solute |
| | B) | decomposed |
| | C) | a(n) solution |
| | D) | a(n) alcohol |
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63 | | Inorganic substances dissolve in water or react with water to release ions. Thus they are known as |
| | A) | salts |
| | B) | electrolytes |
| | C) | bases |
| | D) | inorganic compounds |
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64 | | Inorganic compounds do not contain which of the following bonds? |
| | A) | carbon and hydrogen |
| | B) | nitrogen and hydrogen |
| | C) | oxygen and hydrogen |
| | D) | carbon and sulfur |
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65 | | Most metabolic reactions occur in |
| | A) | alcohol |
| | B) | blood |
| | C) | carbon dioxide |
| | D) | water |
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66 | | To maintain homeostasis which of the following conditions are necessary? |
| | A) | Electrolytic imbalance is necessary. |
| | B) | Water volume has to be very low. |
| | C) | Electrolyte balance is key for maintaining homeostasis. |
| | D) | There should not be any formation of ions. |
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67 | | Which statement regarding the role of water in the body is true? |
| | A) | Water can absorb and transport heat. |
| | B) | Water is the most abundant compound in the body. |
| | C) | Water carries nutrients as well as waste materials. |
| | D) | All of the above statements are true regarding the role of water in the body. |
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68 | | Some inorganic compounds like __________mostly known as harmful are also required for some of the vital body functions. |
| | A) | NO and CO |
| | B) | H2O and CO2 |
| | C) | NaCl and PO4 |
| | D) | NH4 and O2 |
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69 | | Carbon dioxide in our body is present |
| | A) | after the reaction occurs to synthesize protein |
| | B) | as a genetic factor |
| | C) | as a result of respiration |
| | D) | as a necessary compound for our body structure |
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70 | | Saline given to a patient to avoid dehydration is a solution of |
| | A) | sodium chloride |
| | B) | carbon dioxide |
| | C) | oxygen in water |
| | D) | sodium bicarbonate |
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71 | | Substances dissolved in the liquid portion of a solution are called the |
| | A) | solutes |
| | B) | solvents |
| | C) | catalysts |
| | D) | osmoles |
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72 | | Organic compounds are those that always contain |
| | A) | carbon and oxygen |
| | B) | carbon and hydrogen |
| | C) | hydrogen and oxygen |
| | D) | sulfur and phosphorus |
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73 | | Carbohydrates are also known as |
| | A) | harmful chemicals |
| | B) | primary source of energy |
| | C) | necessary components for protein formation |
| | D) | unsaturated compounds |
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74 | | A simple carbohydrate is characterized by |
| | A) | having a molecular formula of C6H12O6 |
| | B) | being a building block of nucleic acids |
| | C) | having several polypeptide chains joined together |
| | D) | having too many double bonds |
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75 | | There are four vital organic compounds in the human body; those are |
| | A) | carbohydrates, lipids, proteins, and nucleic acids |
| | B) | proteins, cholesterol, hydrocarbons, and sodium chloride |
| | C) | carbohydrate, protein, plastic, and nucleic acid |
| | D) | sodium chloride, carbon dioxide, calcium carbonate, phospholipid |
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76 | | A major function of Deoxyribo Nucleic Acids (DNA) is that DNA |
| | A) | helps in the synthesis of varieties of nucleic acids |
| | B) | is important in building muscles |
| | C) | stores genetic information |
| | D) | is important in building carbohydrates |
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77 | | Which of the following statements about lipids is true? |
| | A) | Lipids are insoluble in water. |
| | B) | Cholesterol and fats are different varieties of lipids. |
| | C) | Fat molecules contain C, H, and O, but the proportion of oxygen is much smaller than in carbohydrates. |
| | D) | All of the above statements are true about lipids. |
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78 | | A general characteristic of nucleic acids is that they are |
| | A) | very small, simple molecules |
| | B) | a combination of inorganic and organic compound |
| | C) | all composed of building blocks called nucleotides |
| | D) | a type of inorganic compound |
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79 | | A protein can become denatured when |
| | A) | bonds between C-O are broken |
| | B) | weak hydrogen bonds are broken |
| | C) | peptide bonds are broken |
| | D) | none of the above |
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80 | | Which of the following statements about proteins is true? |
| | A) | Proteins are necessary for body structure and they serve as energy sources, and chemical messengers. |
| | B) | Proteins are made up with C, H, O, and N, and sometimes S. |
| | C) | They can act as enzymes. |
| | D) | All of the above statements are about proteins. |
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81 | | Which of the following is an organic compound? |
| | A) | hydrochloric acid (HCl) |
| | B) | salt (NaCl) |
| | C) | glucose (C6H12O6) |
| | D) | water (H2O) |
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82 | | The molecule used most frequently by cells as a fuel belongs to which of the following groups? |
| | A) | prostaglandins |
| | B) | carbohydrates |
| | C) | nucleic acids |
| | D) | steroids |
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83 | | Proteins are composed of building blocks called |
| | A) | triacylglycerols |
| | B) | phospholipids |
| | C) | amino acids |
| | D) | monosaccharides |
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