Molecular Biology questions and answers

21

KEY for Review 2 

1. C 

2. D 

3. B 

4. A 

5. C 

6. A 

7. A 

8. E 

9. C 

10. C 

11. A 

12. C 

13. C 

14. D 

15. B 

16. D 

17. E 

18. A 

19. A 

20. B 

21. B 

22. A 

23. B 

24. B 

25. E 

26. C 

27. A 

28. A 

29. A 

30. E 

31. C 

32. E 

33. C 

34. B 

35. A 

36. B 

37. A 

38. B 

39. C 

40. A 

41. D 

42. B 

43. A 

44. C 

45. D 

46. A 

47. E 

48. C 

49. C 

50. A 

22

Review 3: Answer Key on page 31 

Select the correct answer. 

 
1) Science is; 
 

A) A field of study that requires certain “laws of nature” to be taken on    

               faith 
 

B) Both a body of knowledge and an intellectual activity encompassing  

               observation, description, experimentation, and explanation of natural   
               phenomena 
 

C) A process that can be applied only within the scientific disciplines, such as  

               biology, chemistry, and physics 
 

D) The only way to understand the world 

E) A field of study that determines ethical standards for the human  

               Population 
 
2) What best describes a control group in an experiment? 
 

A) The condition that is being tested 

B) A sample taken through all experimental steps except the one being  

               tested 
 

C) A variable that changes throughout the experiment 

D) The dependent variable 

E) A condition that is different in every way from what is being tested 

 
3) Which group is the most abundant in terms of numbers of individuals? 
 A) 

Animals 

 B) 

Fungi 

 C) 

Eukarya 

 D) 

Plants 

 E) 

Prokaryotes 

 
4) Which of the following is a multicellular organism 
 A) 

Heart 

B) Cardiovascular system 

 C) 

Bacterium 

D) Forest ecosystem 

 E) 

Cockroach 

 
5) Which of the following are universal characteristics of life? 
 

A) The ability to grow and the ability to reproduce using DNA 

B) The ability to reproduce using DNA and the ability to capture energy  

               from the sun 
 

C) The ability to move and the ability to see and smell 

D) The ability to grow and the ability to photosynthesize 

E) The ability to organize and the ability to become dormant 

23

6) Metabolism refers to an organism’s ability to  
 A) 

Reproduce 

B) Use energy 

C) Pass on genetic information 

D) Respond to the environment 

E) All of the above 

7) A cell that lacks membranous organelles is a(n): 
          A) Member of the Plant kingdom 
 

B) Animal cell 

C) Prokaryotic cell 

D) A protist 

E) Eukaryotic cell 

 
8) An atom has 5 electrons in its outer orbit.  To complete its outer orbit it needs  
     __ electrons. 
 A) 

5 

 B) 

3 

 C) 

2 

 D) 

1 

 E) 

8 

 
9) Electrons 
 

A) Located closest to the nucleus have the most energy 

B) Along with neutrons, are located in the nucleus 

C) Are attracted to the negatively charged nucleus 

D) Are negatively charged 

E) Have an amu = 1 

 
10) Water can absorb and store a large amount of heat while increasing only a few  
       degrees in temperature.  Why? 
          A) The heat must first be used to break the hydrogen bonds rather than  

raise the temperature. 
 

B) The heat must first be used to break the ionic bonds rather than raise    

the temperature 
 

C) The heat must first be used to break the covalent bonds rather than  

                raise the temperature 
 

D) An increase in temperature causes an increase in the adhesion of water 

E) An increase in temperature causes an increase in the cohesion of water 

 
11) Milk of magnesia, which had a pH of 10, is often used to treat a stomach upset. 
     Milk of magnesia ___? 
          A) Is a base 
 

B) Is hydrophobic 

C) Is a salt 

D) Is an acid 

E) Has the same pH as stomach acid 

24

12) A molecule of glucose has the molecular formula C

6

H

12

O

6

.  Therefore it has __  

      atoms. 
          A) 3 
 B) 

12 

 C) 

6 

 D) 

24 

E) None of the above 

 
13) Which of the following provides some energy 

storage

 for animals? 

 A) 

Glucose 

 B) 

Glycogen 

 C) 

Cellulose 

 D) 

Starch 

 E) 

Ribose 

 
14) Tr

iglycerides are: 

A) Polymers of amino acids 

B) Always composed of carbon rings 

C) Lacking carboxyl groups (COOH) 

D) Nonpolar and hydrophobic 

E) Made from glycerol and nucleic acids

 
15) Which of the following is NOT an organic molecule? 
 A) 

Protein 

 B) 

Nucleic 

acid 

 C) 

Monosaccharide 

D) Carbon dioxide 

 E) 

Lipid 

 
16) Which of the following is NOT one of the four most common elements found in  
      living organisms? 
          A) Hydrogen 
 B) 

Carbon 

 C) 

Oxygen 

 D) 

Sulfur 

 E) 

Nitrogen 

 
17) What type of chemical reaction results in the breakdown of organic polymers  
      into their respective subunits? 
 A) 

Condensation 

 B) 

Hydrolysis 

 C) 

Oxidation 

 D) 

Ionization 

 E) 

Dehydration 

25

18) All of the following are components of modern cell theory EXCEPT: 
          A) All living organisms are made up of one or more cells 
 

B) The smallest living organisms are single cells 

C) All cells arise from preexisting cells 

D) Bacterial cells are eukaryotic 

E) Cells are the functional units of all organisms 

 
19) Which of the following organelles would only be found within a cell that was  
       both eukaryotic and autotrophic? 
 A) 

Mitochondria 

B) Smooth endoplasmic reticulum 

 C) 

Nucleus 

D) Golgi apparatus 

 E) 

Chloroplast 

 
20) Which statement is NOT true about bacteria? 
 

A) Their cell wall is composed of the same material as plant cell walls 

B) Some can move because they have flagella 

C) Some can photosynthesize 

D) They are all prokaryotes 

E) Their cell wall contains peptidoglycan 

 
21) Which of the following statements about the plasma membrane is/are true? 
 

A) It is a solid layer of proteins that protects the contents of the cell 

B) The plasma membrane of the bacterium has none of the same components  

     as the plasma membrane of a eukaryotic cell 

C) It is a rigid and unmoving layer of phospholipids and proteins 

D) It allows selected molecules to pass into and out of the cell 

E) C and D are correct 

 
22) If a living plant were moved from a freshwater aquarium to a saltwater  
       aquarium, which of the following would occur? 
 

A) Nothing – the plant would do equally well in either aquarium 

B) The plant’s cells would lose water 

C) The plant’s cells would lose ions 

D) The plant’s cells would take up water 

E) The plant would gain turgor pressure 

 
23) Which phrase does NOT describe one of the functions of proteins of the  
       plasma/cell membrane? 
 

A) Forming a channel through the membrane 

B) Initiating the replication of genetic material 

C) Binding to a substance to carry it through the membrane 

D) Acting as a receptor for substances outside the cell 

E) Maintaining Na

+

/K

+

 balance in cell 

26

24) Which of the following is true about ribosomes? 
          A) They contain RNA and proteins 
 

B) They synthesize proteins 

C) They are formed on the cytoskeleton 

D) They are found only in the nucleus 

E) A and B 

 
25) The cells that line our respiratory tract, and covering one-celled paramecia  
        both have these hair-like projections.. 
          A) Cilia 
 B) 

Flagella 

 C) 

Microfilaments 

 D) 

Centrioles 

 E) 

Pili 

 
26) Which form of energy is NOT correctly associated with an example? 
          A) Kinetic energy: fat molecules 
 

B) Kinetic energy: movement of molecules 

C) Chemical energy: glucose 

D) Potential energy: water behind a dam 

E) Potential energy: ATP 

 
27) If a reaction results in one molecule losing an electron and a second molecule  
       gaining that electron, the electron donor is said to be 
          A) Reduced 
 B) 

Oxidized 

 C) 

Transformed 

 D) 

Activated 

 E) 

Inhibited 

 
28) Lactose is a disaccharide of glucose and galactose, and its digestion requires  
      the actions of the enzyme lactase to break lactose into monosaccharides. 
      If lactose is eaten as part of the diet but is not digested by lactase, this sugar  
      is then metabolized by bacteria in the intestine, leading to the symptoms of  
      lactose intolerance.  Lactose intolerance, therefore, results from a(n): 

A) Lack of hydrolysis of lactose 

          B) Lack of dehydration synthesis of lactose 
          C) Low blood lactose level 
 

D) Inability of the body to produce lactose 

E) Lack of glucose in the diet 

 
29) Which molecule attaches to pyruvate after glycolysis and before Krebs cycle? 
          A) Lactate 
 B) 

Acetyl-CoA 

C) Citric acid 

 D) 

NADH 

 E) 

Oxygen 

27

30) What is the significance of the conversion of pyruvate to lactate during  
       fermentation? 
 

A) Pyruvate becomes available to enter the mitochondrial matrix 

B) The citric acid/Krebs cycle is initiated 

C) NAD+ is regenerated for use in glycolysis 

D) ATP is produced 

E) The energy in pyruvate is used up 

 
31) The first process in breaking down glucose is 
          A) Krebs cycle 
 B) 

Fermentation 

 C) 

Chemiosmosis 

 D) 

Glycolysis 

E) Preparatory Step 

 
32) Which of the following molecules can be modified to enter the citric  
       acid/Krebs cycle? 
          A) Pyruvate 
 

B) Amino Acids 

C) Fatty Acids 

D) None of the above 

E) All of the above 

 
33) Because one strand of the double-stranded helix is found in each daughter cell,  
      the replication process is called 
 A) 

Proofreading 

 B) 

Polymerizing 

 C) 

Semiconservative 

 D) 

Redundant 

 E) 

Duplication 

 
34) In a DNA molecule, base pairing occurs between: 

A) Adenine and thymine 
B) Adenine and guanine 
C) Guanine and uracil 
D) Thymine and cytosine 

E) Adenine and uracil 

 
35) During which phase of the eukaryotic cell cycle does DNA and chromosome  
       replication occur? 
 

A) The S phase of interphase 

B) The G1 phase of interphase 

C) The mitotic phase 

 D) 

Cytokinesis 

E) The G2 phase of interphase 

28

36) When a cell divides via mitosis: 
 

A) Each daughter cell receives a nearly perfect copy of the parent cell's  

    genetic information 

B) Each daughter cell receives exactly half the genetic information in the 

    parent cell 

C) Each daughter cell receives the same amount of genetic information that  

               was in the parent cell, but it has been significantly altered 
 

D) The genetic information is randomly parceled out to the daughter cells 

E) Each daughter cell contains unique genetic information 

 
37) Meiotic cell division occurs in the ____, and results in the production of ____ 
 

A) Body cells; daughter cells 

B) Body cells; parent cells 

C) Germ-line; gametes 

D) Testes and ovaries; diploid cells 

E) Somatic cells; haploid cells 

38) In the comparison of a DNA molecule to a twisted ladder, the upright sides  
 

of the ladder are: 

A) Nitrogenous bases linked together. 

B) Deoxyribose linked to phosphate. 

C) Deoxyribose linked to sulfate. 

D) Nitrogenous bases linked to phosphate. 

E) Hydrogen bonds between bases. 

 
39) A “mini-gene” has the base sequence TACCCGTGCACG.  Which of the following  
      sequences represents a single base substitution? 

 A) TACCCGTGCACG 

                             B) TACCCGAGCACG 
                             C) TACCCGGCACG 
                             D) TACCCGTGTCACG 

 E) TACCGTGCTACG 

 
40) All of the following statements about genotypes and phenotypes are true  
       EXCEPT: 
 

A) Individuals with the same phenotype might have different genotypes. 

B) Matings between individuals with dominant phenotypes cannot produce  

     offspring with recessive phenotypes. 

C) Matings between individuals with recessive phenotypes usually do not  

    produce offspring with dominant phenotypes. 

D) Individuals with the same genotype might have different phenotypes 

E) None of the above statements are true 

29

41) Which of the following is NOT true about mutations? 
 

A) Damage to DNA can result after exposure to some environmental factors 

B) Mutations can often be repaired by enzymes 

C) Variations in DNA and mutations are important for evolution to occur 

D) All mutations are harmful for the organism 

E) Ultraviolet light can cause mutations 

 
42) Choose the correct pathway of information flow in the cell. 
 A) 

RNA 

→

 DNA 

→

 protein 

 B) 

DNA 

→

 RNA 

→

 protein 

 C) 

ER 

→

 DNA 

→

 RNA 

→

 protein 

 D) 

ER 

→

 DNA 

→

 Golgi 

→

 protein 

E) Ribosomal RNA 

→

 DNA 

→

 protein 

 
43) Which of the classes of RNA molecules is part of the process of transcription? 
 

A) Ribosomal RNA 

B) Transfer RNA 

C) Messenger RNA 

 D) 

Primary 

RNA 

E) Secondary RNA 

 
44) Which of the classes of RNA molecules is/are part of the process of  
       translation? 
 

A) Ribosomal RNA 

B) Transfer RNA 

C) Messenger RNA 

D) A and C 

E) A, B and C 

45) All of the following are directly involved in translation EXCEPT: 
          A) Ribosomes 
 B) 

tRNA 

C) Amino acids 

 D) 

DNA 

 E) 

mRNA 

 
46) Darwin realized that most species produce many more offspring than is  
       necessary to maintain a constant population yet the size of the population  
       normally doesn’t change much.  These “extra” individuals that are born: 
          A) Migrate to another location 
 

B) Die before they can reproduce 

C) Evolve to become new species 

D) Mutate and are able to adapt to new environments 

E) Mate with other species 

30

47) A broad definition of a fossil is: 
 

A) Any preserved trace or remnant of an organism from the past, usually at  

                least 10,000 years old 
 

B) The preserved pieces of hard parts of an organism, such as shell or bone 

C) The preserved bones of vertebrates 

D) A piece of an organism that has turned into a rock 

E) The process of preservation of intact animal bodies 

 
48) The human appendix is an example of a(n): 
          A) Analogous structure 
 

B) Homologous structure 

C) Vestigial structure 

 D) 

Adaptation 

 E) 

Mutation 

 
49) Of all the possible amino acids, all living organisms make use of only the same  
       20 amino acids.  This supports the idea that: 
 

A) Only a limited number of DNA mutations are possible 

B) Bacteria, animals, and plants developed independently 

C) Each species uses a unique set of amino acids 

D) Plants and animals have a completely different ancestry 

E) All living things are derived from a common ancestor 

 
50) Which is NOT an example of evolution? 
 

A) Development of antibiotic-resistant bacteria. 

B) Flightless birds on islands without predators. 

C) This year's flu is different from last year's flu. 

D) A dog learns how to open the cabinet where its food is kept 

E) Most commercial pesticides are effective for 2-3 years. 

31

KEY for Review 3 

1. B 

2. B 

3. E 

4. E 

5. A 

6. B 

7. C 

8. B 

9. D 

10. A 

11. A 

12. D 

13. B 

14. D 

15. D 

16. D 

17. B 

18. D 

19. E 

20. A 

21. D 

22. B 

23. B 

24. E 

25. A 

26. A 

27. B 

28. A 

29. B 

30. C 

31. D 

32. E 

33. C 

34. A 

35. A 

36. A 

37. C 

38. B 

39. B 

40. B 

41. D 

42. B 

43. C 

44. E 

45. D 

46. B 

47. A 

48. C 

49. E 

50. D