PHYSIO: chapter 3 practice questions
67. How many genes does it appear that humans have? A. 25,000 B. 100,000 C. 3 million D. 3 billion
A. 25,000
111. Which stage of the cell cycle immediately precedes the S phase? A. G1 B. G2 C. M D. None apply
A. G1
59. What organelle functions to chemically modify cellular products and package them in vesicles? A. Golgi complex B. mitochondrion C. lysosome D. ribosome
A. Golgi complex
87. Which of the following is NOT true of siRNA? A. It can silence up to 200 different mRNAs. B. It is short and doublestranded. C. It is processed by an enzyme called Dicer. D. It may be used to genetically suppress genes involved in disease.
A. It can silence up to 200 different mRNAs.
93. _____________ RNA has the function of bringing amino acids to the ribosome during translation. A. Transfer B. Messenger C. Ribosomal D. Nuclear
A. Transfer
77. What chemical change occurs to histones that will turn on genetic transcription? A. acetylation B. acidification C. phosphorylation D. differentiation
A. acetylation
95. Protein synthesis requires A. aminoacyltRNA synthetase to link amino acids to specific tRNA molecules. B. secreted proteins to be synthesized by cytosolic polyribosomes. C. recognition of the anticodon in mRNA by the codon in tRNA. D. the presence of transcription factors.
A. aminoacyltRNA synthetase to link amino acids to specific tRNA molecules.
131. Chromosomes move to opposite poles in A. anaphase. B. metaphase. C. prophase. D. telophase.
A. anaphase.
42. The pH of the cytoplasm is more ___________ than the interior of a primary lysosome. A. basic B. acidic C. neutral
A. basic
133. The pericentriolar material is believed to be responsible for A. cytoskeletal organization. B. centriole replication. C. kinetochore formation. D. centrosome formation.
A. cytoskeletal organization.
75. Chromatin that is active in genetic transcription is called A. euchromatin. B. homochromatic. C. heterochromatin. D. embryonic chromatin.
A. euchromatin.
22. Release of neurotransmitters occurs via A. exocytosis. B. endocytosis. C. phagocytosis. D. pinocytosis.
A. exocytosis.
130. Growth due to increased cell size is called A. hypertrophy. B. hyperplasia. C. atrophy. D. dystrophy.
A. hypertrophy.
144. Crossing over is important for A. increasing genetic variability. B. preventing mutations. C. limiting genetic recombination. D. maintaining chromosome structure.
A. increasing genetic variability.
37. Which of the following is NOT a molecular motor used to move substances along the cytoskeleton? A. melanin B. kinesin C. myosin D. dynein
A. melanin
49. The organelle involved in the production of energy is the A. mitochondrion. B. ribosome. C. cytoskeleton. D. centriole.
A. mitochondrion.
63. Proteins and mRNA exit the nucleus via A. nuclear pores. B. endoplasmic reticulum. C. vesicles. D. centromeres.
A. nuclear pores.
7. Proteins located on the surface of the plasma membrane can act as ___________ for hormones. A. receptors B. enzymes C. neurotransmitters D. pseudopods
A. receptors
139. The movement of chromosomes during mitosis is due to A. spindle fibers. B. telomeres. C. chromatids. D. actin and myosin.
A. spindle fibers.
141. This organ contains cells that are haploid: A. the testis B. the liver C. the lung D. the heart
A. the testis
104. Regulatory proteins are degraded outside of lysosomes by binding to ___ and then broken down by the proteasome. A. ubiquitin B. chaperones C. lysosomes D. ribosomes
A. ubiquitin
69. How many proteins does it appear that humans can produce? A. 25,000 B. 100,000 C. 3 million D. 3 billion
B. 100,000
92. Huntington's disease is characterized by a dominant defective gene on chromosome A. 2. B. 4. C. 19. D. 21.
B. 4.
109. What enzyme breaks the hydrogen bonds between the bases of DNA in preparation for replication? A. DNA polymerase B. DNA helicase C. spliceosome D. cyclin D
B. DNA helicase
76. Chromatin is comprised of _____________ and ___________. A. phospholipids, DNA B. DNA, protein C. RNA, protein D. DNA, RNA
B. DNA, protein
79. What enzyme is needed for transcription? A. spliceosomes B. RNA polymerase C. RNA promoter D. DNA polymerase
B. RNA polymerase
32. A flagellum has A. a "9+0" structure. B. a "9+2" structure. C. no microtubules. D. microvilli as its structure.
B. a "9+2" structure.
39. Which of the following is NOT an example of an inclusion? A. glycogen B. actin C. melanin D. triglycerides
B. actin
102. The Golgi apparatus is involved in A. intracellular calcium storage. B. adding carbohydrates to proteins. C. degradation of organelles. D. mitotic chromosomal movement.
B. adding carbohydrates to proteins.
135. Telomeres serve to A. increase apoptosis. B. cap the ends of DNA and protect it from damage. C. break DNA and cause it to degrade. D. cause replication of genes.
B. cap the ends of DNA and protect it from damage.
48. What enzyme is needed to prevent excessive accumulation of hydrogen peroxide from peroxisome activity? A. peroxidase B. catalase C. oxidate D. maltase
B. catalase
94. The _____________ of the messenger RNA is recognized by the _____________ of the transfer RNA. A. triplet, codon B. codon, anticodon C. anticodon, codon D. anticodon, triplet
B. codon, anticodon
116. The duration of the cell cycle is decreased in response to increased amounts of A. telomerase. B. cyclin C. DNA helicase. D. proteasome.
B. cyclin
138. The division of the cytoplasm in mitosis is called A. anaphase. B. cytokinesis. C. senescence. D. kinetochore.
B. cytokinesis.
72. Which of the following is NOT an explanation for how one gene can produce more than one protein? A. posttranslational methylation and phosphorylation B. different groups of polypeptides associating to make different proteins C. various cuts and splices of mRNA D. different carbohydrates bonded to the protein
B. different groups of polypeptides associating to make different proteins
12. How are the phospholipids arranged to form the plasma membrane? A. single layer with hydrophilic heads outward B. double layer with hydrophobic tails facing inward toward each other C. double layer with hydrophilic heads facing inward toward each other D. double layer with phospholipids on the outside and proteins on the inside
B. double layer with hydrophobic tails facing inward toward each other
11. Which of the following is NOT a function of membrane proteins? A. transport B. energy production C. structural support D. receptors
B. energy production
78. Embryonic stem cells are pluripotent and their chromatin is mostly A. mesenchymal. B. euchromatin. C. heterochromatin. D. histochromatin.
B. euchromatin.
129. Growth due to an increase in cell number is called A. hypertrophy. B. hyperplasia. C. atrophy. D. dystrophy.
B. hyperplasia.
134. Cellular senescence may be prevented by A. increased DNA polymerase activity. B. increased telomerase activity. C. increased RNA polymerase activity. D. increased synthase activity.
B. increased telomerase activity.
83. PremRNA contains noncoding regions called A. exons. B. introns. C. small nuclear ribonucleoproteins (snRNPs). D. spliceosomes.
B. introns.
43. TaySachs disease is caused by a genetic defect which affects the activity of _______ enzymes. A. mitochondrial B. lysosomal C. centrosomal D. ribosomal
B. lysosomal
123. Cells which will undergo apoptosis would contain large numbers or quantities of A. centrioles. B. lysosomes. C. golgi apparatus. D. rough endoplasmic reticulum.
B. lysosomes.
142. This process is also known as reduction division: A. cell division B. meiosis C. mitosis D. genetic translation
B. meiosis
146. Gene silencing may be accomplished by A. removal of the gene. B. methylation of cytosine bases in DNA. C. crossing over. D. genetic recombination.
B. methylation of cytosine bases in DNA.
33. Folds of the plasma membrane that increase surface area are called A. cilia. B. microvilli. C. flagella. D. vesicles.
B. microvilli.
34. Cells with large numbers of microvilli on their apical surface are probably involved in A. movement of the body. B. reabsorption of molecules during production of urine. C. detoxification of chemicals. D. secretion of neurotransmitters.
B. reabsorption of molecules during production of urine.
40. Which type of lysosome contains undigested wastes? A. secondary lysosome B. residual body C. primary lysosome D. tertiary body
B. residual body
53. The organelle that acts as enzymes for protein synthesis is the A. mitochondrion. B. ribosome. C. nucleolus. D. lysosome.
B. ribosome.
107. DNA replication is A. conservative. B. semiconservative. C. dispersive. D. both semiconservative and dispersive.
B. semiconservative.
26. The only flagellated cells in humans are A. ova. B. sperm. C. goblet cells. D. tumor cells.
B. sperm.
126. Germinal cells can most likely divide indefinitely due to the activity of an enzyme called A. caspases. B. telomerase. C. DNA polymerase. D. RNA transferase.
B. telomerase.
127. Loss of DNA sequences at the ends of chromosomes in the ________ region may cause cell senescence. A. centromere B. telomere C. mitotic D. anticodon
B. telomere
25. Phagocytosis differs from endocytosis in that with phagocytosis A. the plasma membrane invaginates to produce a furrow that pinches off inside the cell. B. the plasma membrane extends outwards with pseudopods to surround the substance. C. specific membrane receptors bind to the molecules to be brought into the cell. D. None apply.
B. the plasma membrane extends outwards with pseudopods to surround the substance.
137. Telomere DNA is produced from a ______________ template. A. DNA B. telomerase C. RNA D. ATP
C. RNA
122. Damage to cellular DNA that cannot be repaired would induce A. mitosis. B. meiosis. C. apoptosis. D. cell division.
C. apoptosis.
44. What process involves the destruction of wornout organelles by lysosomes? A. exocytosis B. pinocytosis C. autophagy D. None apply.
C. autophagy
101. A cell lacking a Golgi apparatus would not be able to add _____________ to proteins. A. lipids B. proteins C. carbohydrates D. acids
C. carbohydrates
121. Apoptosis involves the activation of enzymes called ____________, which are the cell "executioners" that activate other enzymes in the nucleus that fragment the DNA. A. neutrophils B. lysosomes C. caspases D. peroxisomes
C. caspases
124. The family of enzymes in cells activated during apoptosis are A. necrotic enzymes. B. chromatids. C. caspases. D. centromeres.
C. caspases.
51. The folded inner membrane of a mitochondrion is called A. rugae. B. plicae. C. cristae. D. microvilli.
C. cristae.
90. Genetic translation occurs in ribosomes located in the _____________ of the cell. A. nucleus B. plasma membrane C. cytoplasm D. Golgi apparatus
C. cytoplasm
36. Microtubules and microfilaments are the primary components of the A. cytosol. B. nucleus. C. cytoskeleton. D. plasma membrane.
C. cytoskeleton.
2. The _____________ is the liquid portion of the cell between the plasma membrane and nucleus. A. cytoskeleton B. peroxisome C. cytosol D. phospholipids
C. cytosol
21. The process by which cells secrete cellular products into the extracellular environment is A. phagocytosis. B. endocytosis. C. exocytosis. D. pinocytosis.
C. exocytosis.
62. The process of gene expression occurs as A. genetic transcription and genetic transduction. B. genetic translation and genetic degradation. C. genetic transcription and genetic translation. D. genetic transduction and genetic degradation.
C. genetic transcription and genetic translation.
57. Cells actively involved in secreting proteins would contain large numbers or quantities of A. lysosomes. B. peroxisomes. C. granular (rough) endoplasmic reticulum. D. agranular (smooth) endoplasmic reticulum.
C. granular (rough) endoplasmic reticulum.
132. Centrosomes replicate during A. anaphase. B. cytokinesis. C. interphase. D. telophase.
C. interphase.
89. microRNA A. is singlestranded. B. is complementary to a particular mRNA C. is partially complementary to many mRNAs. D. is produced in large numbers by tumor cells.
C. is partially complementary to many mRNAs.
128. Chromosomes are lined up at the equator of the cell during this stage of mitosis: A. prophase B. anaphase C. metaphase D. telophase
C. metaphase
120. The process of tissue death in which cells swell, rupture their membranes, and burst is called A. apoptosis. B. phagocytosis. C. necrosis. D. transcytosis.
C. necrosis.
68. The spooling of DNA around histones creates particles called A. nucleoli. B. proteosomes. C. nucleosomes. D. euchromatin.
C. nucleosomes.
147. In epigenetic inheritance A. both homologous chromosomes are inactivated. B. one set of the homologous chromosomes are silenced. C. one allele of a homologous pair is expressed. D. None apply.
C. one allele of a homologous pair is expressed.
8. Proteins that are partially embedded on one side of the plasma membrane are A. integral proteins. B. transport proteins. C. peripheral proteins. D. fluid proteins.
C. peripheral proteins.
45. A cell which is actively involved in the detoxification of chemicals would contain large quantities of A. ribosomes. B. mitochondria. C. peroxisomes. D. rough endoplasmic reticulum.
C. peroxisomes.
47. Membrane enclosed organelles containing oxidative enzymes that form hydrogen peroxide are A. lysosomes. B. centrosomes. C. peroxisomes. D. chromosomes.
C. peroxisomes.
17. Particulate matter is nonspecifically taken into cells by the process of A. exocytosis. B. phagocytosis. C. pinocytosis. D. receptormediated endocytosis.
C. pinocytosis.
143. Crossing over occurs during A. anaphase I of meiosis. B. metaphase of mitosis. C. prophase I of meiosis. D. metaphase II of meiosis.
C. prophase I of meiosis.
20. Intake of a specific molecule from the extracellular compartment by a cell occurs through A. phagocytosis. B. exocytosis. C. receptormediated endocytosis. D. apoptosis.
C. receptormediated endocytosis.
27. Which of the following locations have ciliated cells? A. respiratory and digestive systems B. female reproductive and lymphatic systems C. respiratory and female reproductive systems D. digestive and lymphatic systems
C. respiratory and female reproductive systems
56. Ribosomal enzymes needed for protein synthesis are called A. catalases. B. superoxide radicals. C. ribozymes. D. lysozymes.
C. ribozymes.
65. Which of the following is NOT true of the nuclear envelope? A. doublelayered B. fused in areas by nuclear pore complexes C. singlelayered D. contains nuclear pores
C. single layered
105. Why is it necessary for the cell to degrade some cellular proteins? A. to eliminate incorrectly folded proteins B. to remove specific enzymes and plasma membrane proteins C. for tight control of the cell cycle D. All apply
D. All apply
18. Phagocytosis is important for A. body defense against foreign organic matter. B. promoting inflammation. C. removal of old and dying cells. D. All apply.
D. All apply.
28. The centrosome is responsible for A. making cilia. B. making microtubules. C. pulling duplicated chromosomes apart. D. All apply.
D. All apply.
86. Small RNA and protein regions are joined together to make functional mRNA by A. spliceosomes. B. introns. C. snRNPs. D. Both spliceosomes and snRNPs are correct.
D. Both spliceosomes and snRNPs are correct.
97. ______ molecules aid in the folding of a polypeptide chain into its tertiary structure. A. Spliceosome B. Ubiquitin C. Centrosome D. Chaperone
D. Chaperone
91. A codon codes for a(an) A. mRNA. B. fatty acid. C. carbohydrate. D. amino acid.
D. amino acid.
119. The process of cell death in which cell membranes remain intact but become bubbled and the nuclei condense is known as A. endocytosis. B. phagocytosis. C. exocytosis. D. apoptosis.
D. apoptosis.
10. The flexibility of a cell's membrane is determined by the ratio of _____________ to ___________. A. protein, carbohydrate B. cholesterol, protein C. phospholipids, protein D. cholesterol, phospholipids
D. cholesterol, phospholipids
145. Genes that have been silenced are passed to daughter cells during mitosis and meiosis in a process called A. apoptosis. B. necrosis. C. hypertrophy. D. epigenetic inheritance.
D. epigenetic inheritance.
106. In the nucleus of a diploid cell, the amount of cytosine would equal the amount of A. adenine. B. thymine. C. uracil. D. guanine.
D. guanine.
9. The plasma membrane is referred to as a mosaic because of the presence of A. stationary proteins in a uniform arrangement. B. carbohydrates in changing patterns. C. phospholipids that are in constant motion. D. moving proteins in a random arrangement.
D. moving proteins in a random arrangement.
64. The function of the _____________ is to produce ribosomal RNA. A. chromatin B. centromere C. lysosomes D. nucleolus
D. nucleolus
117. Oncogenes A. prevent formation of cancer cells. B. block the ability of cyclins to stimulate cell division. C. stimulate apoptosis. D. often stimulate cyclindependent kinases that speed up the G1 phase.
D. often stimulate cyclindependent kinases that speed up the G1 phase.
140. Meiosis is only observed in the _____________ and ___________. A. skin, finger nails B. ovaries, breasts C. testes, skin D. ovaries, testes
D. ovaries, testes
103. Which of the following is NOT a function of the Golgi complex? A. packaging final proteins in vesicles B. modifying proteins C. separation of different types of proteins D. removal of the leader sequence from the protein
D. removal of the leader sequence from the protein
60. The process of recycling cellular proteins that had been released by exocytosis and brought back into the cell is called A. mediated transport. B. active transport. C. autophagy. D. retrograde transport.
D. retrograde transport.
58. Cells which contain large numbers of mitochondria and large amounts of agranular (smooth) endoplasmic reticulum are most likely A. bladder cells. B. bone cells. C. lung cells. D. skeletal muscle cells.
D. skeletal muscle cells.
100. The primarily hydrophilic leader sequence of secretory proteins allows it to be inserted into the cisterna of the endoplasmic reticulum.
FALSE
110. Cells in the G1 phase will have their chromosomes in a condensed form.
FALSE
112. Protooncogenes are mutated forms of normal genes which contribute to cancer.
FALSE
114. One example of a tumor suppressor gene is p53, which protects against cancer by directly blocking the ability of cyclins to stimulate cell division.
FALSE
115. Knockdown mice are mice strains in which a specific targeted gene has been inactivated.
FALSE
125. Growth of a tissue due to hypertrophy occurs when cells increase in number.
FALSE
13. Large hydrophilic molecules can readily move unaided into and out of cells.
FALSE
23. Pinocytosis is a type of exocytosis.
FALSE
29. All body cells have motile cilia with a "9+2" structure.
FALSE
3. The plasma membrane is a static, uniform structure that protects the cells and controls the passageway of materials into and out of the cell.
FALSE
38. Chemicals stored in cells are called kinesins.
FALSE
41. Primary lysosomes consist of digestive enzymes and the contents of a food vacuole.
FALSE
46. The main function of the peroxisome is to release energy from food molecules and transform the energy into usable ATP.
FALSE
5. The hydrophobic center of the plasma membrane will restrict the movement of water and fatsoluble substances through the membrane.
FALSE
55. The granular (rough) endoplasmic reticulum is characterized by a lack of ribosomes.
FALSE
6. The body cells that contain plasma membranes with highest cholesterol content are the muscle cells.
FALSE
66. All body cells have a single, centralized nucleus.
FALSE
70. The term proteome refers to all of the genes in a particular individual.
FALSE
73. Genes present in heterochromatin are readily expressed.
FALSE
85. Introns serve no known purpose in protein synthesis.
FALSE
96. Anticodons found in mRNA allow for base pairing with the codons in tRNA.
FALSE
1. The cell is the basic structural and functional unit in the body.
TRUE
108. Cells in the G1 phase of the cell cycle contain half as much DNA as cells in the G2 phase.
TRUE
113. Cyclins are a group of proteins which promote different phases of the cell cycle.
TRUE
118. Cells lacking lysosomes would be unable to undergo apoptosis.
TRUE
136. Crossing over allows for the exchange of genetic material between homologous chromosomes.
TRUE
14. Phagocytosis is a bulk transport process in which the plasma membrane extends as pseudopods around a particle of organic matter.
TRUE
15. Neutrophils and macrophages move through the extracellular matrix by amoeboid movement.
TRUE
16. Pseudopods can be used for both amoeboid movement and phagocytosis.
TRUE
19. Receptormediated endocytosis would allow cells to selectively remove molecules from the extracellular fluid.
TRUE
24. Cholesterol and AIDS viruses are taken into cells by receptormediated endocytosis.
TRUE
30. Almost every body cell has a single nonmotile primary cilium with a "9+0" structure.
TRUE
31. Primary cilia may serve sensory functions such as vision.
TRUE
35. The cytoskeleton of a cell can serve as a railway that can transport organelles and molecules to different intracellular destinations.
TRUE
4. Carbohydrates are primarily associated with the outer surface of the cell membrane.
TRUE
50. Mitochondria contain their own DNA.
TRUE
52. All mitochondria that an individual has came solely from the mother's fertilized egg cell.
TRUE
54. Individuals using anabolic steroids would have increased amounts of agranular (smooth) endoplasmic reticulum in their liver cells.
TRUE
61. Cells synthesizing large quantities of proteins would have numerous nucleoli.
TRUE
71. One possible reason that the proteome is so much larger than the genome is that mRNAs can be spliced in alternative ways thereby increasing the number of products produced from a particular gene.
TRUE
74. The proteins found in chromatin are called histones, are positively charged, and form spools
TRUE
80. Precursor mRNA is larger than the mRNA it forms.
TRUE
81. RNA strands such as siRNA and miRNA can prevent gene expression in mRNA.
TRUE
82. The genetic code is found within DNA.
TRUE
84. Alternative splicing can explain how 1 gene can code for several different proteins.
TRUE
88. miRNA can be made from particular introns that have been removed from premRNA.
TRUE
98. Proteins to be used by the cell will fold into their secondary or tertiary structures at polyribosomes in the cytoplasm.
TRUE
99. Proteins that will be secreted by the cell are made on the granular endoplasmic reticulum.
TRUE
148. Match the statement to the correct part of the cell life cycle. 1. 4. The centromeres split, separating sister chromotids 2. 1. Chromatin is present in the nucleus 3. 3. Spindle fibers attach to the centromeres of the chromosomes 4. 5. The nucleolus reappears 5. 2. Chromosomes line up along the equator of the cell interphase metaphase prophase anaphase telophase
interphase 2 metaphase 5 prophase 3 anaphase 1 telophase 4
