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1 | | The cell membrane is composed primarily of protein molecules embedded in a double layer of ____ molecules. |
| | A) | phospholipid |
| | B) | carbohydrate |
| | C) | nucleic acid |
| | D) | amino acid |
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2 | | Which of the following is not a function of protein in the cell membrane? |
| | A) | structural support |
| | B) | synthesis of DNA |
| | C) | enzymatic control of chemical reactions |
| | D) | receptors for hormones and other arriving regulatory molecules |
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3 | | Which of the following organic molecules is not commonly found in the cell membrane? |
| | A) | carbohydrates |
| | B) | protein |
| | C) | cholesterol |
| | D) | nucleic acids |
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4 | | Which of the following processes results in the formation of a food vacuole within the cell that will subsequently be digested by enzymes from the lysosome? |
| | A) | phagocytosis |
| | B) | pinocytosis |
| | C) | receptor-mediated endocytosis |
| | D) | exocytosis |
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5 | | The ____ are structures that greatly increase the surface area of cell membranes and thereby promote the rapid diffusion of molecules. |
| | A) | cilia |
| | B) | microvilli |
| | C) | flagella |
| | D) | microtubules |
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6 | | Worn-out organelles and phagocytic by-products are characteristically found within the ____, located in the cytoplasm. |
| | A) | primary lysosome |
| | B) | secondary lysosome |
| | C) | residual body |
| | D) | secretory vesicle |
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7 | | DNA molecules can be found both in the nucleus and in the |
| | A) | ribosomes. |
| | B) | lysosomes. |
| | C) | Golgi complex. |
| | D) | mitochondria. |
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8 | | The organelle that stores calcium (Ca2+) in striated muscle cells and is involved in steroid hormone metabolism is the |
| | A) | endoplasmic reticulum. |
| | B) | lysosome. |
| | C) | Golgi complex. |
| | D) | mitochondria. |
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9 | | Membranes folded into cristae, with matrix and energy production, are characteristics of the organelle known as the |
| | A) | ribosome. |
| | B) | lysosome. |
| | C) | Golgi complex. |
| | D) | mitochondria. |
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10 | | Autophagy, a process that destroys worn-out organelles, is a function of the |
| | A) | cytoskeleton. |
| | B) | lysosome. |
| | C) | Golgi complex. |
| | D) | mitochondria. |
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11 | | A gene is best described as a |
| | A) | molecule of freshly synthesized protein. |
| | B) | region of DNA within the nucleus. |
| | C) | section of rough endoplasmic reticulum. |
| | D) | that portion of the ribosome to which the mRNA will attach. |
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12 | | The Human Genome Project has shown that there appear to be ___________ genes in the genome. |
| | A) | 3,000 to 4,000 |
| | B) | 20,000 to 30,000 |
| | C) | 100,000 |
| | D) | 300,000 to 40,000 |
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13 | | The nitrogenous base in DNA that is not found in RNA is |
| | A) | adenine. |
| | B) | guanine. |
| | C) | thymine. |
| | D) | cytosine. |
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14 | | Within the nucleus DNA forms chromatin when it interacts with |
| | A) | nucleosomes. |
| | B) | proteins. |
| | C) | double helix. |
| | D) | nucleoli. |
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15 | | In order for genes that are packaged in chromatin to be expressed the chromatin must undergo |
| | A) | splicing. |
| | B) | acetylation. |
| | C) | deacetylation. |
| | D) | capping. |
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16 | | Introns and exons are found within |
| | A) | pre-mRNA. |
| | B) | mRNA. |
| | C) | rRNA. |
| | D) | tRNA. |
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17 | | The RNA type that diffuses through the nuclear pores to direct the assembly or synthesis of new protein molecules at the ribosomes in the cytoplasm, is |
| | A) | pre-mRNA. |
| | B) | mRNA. |
| | C) | rRNA. |
| | D) | tRNA. |
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18 | | Anticodons would be characteristic of |
| | A) | pre-mRNA. |
| | B) | mRNA. |
| | C) | rRNA. |
| | D) | tRNA. |
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19 | | Translation is best defined as the synthesis of |
| | A) | mRNA, tRNA, and rRNA from DNA in the nucleus. |
| | B) | pre-mRNA only from DNA in the nucleus. |
| | C) | specific proteins from the mRNA base sequence code. |
| | D) | new, complementary strands of DNA in the nucleus. |
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20 | | The RNA type characterized by bending on itself to form a cloverleaf structure that twists further into an upside down "L" shape is called |
| | A) | pre-mRNA. |
| | B) | mRNA. |
| | C) | rRNA. |
| | D) | tRNA. |
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21 | | Aminoacyl-tRNA synthetase is a group of enzymes that join a specific ____ molecule to the end of its complementary tRNA molecule. |
| | A) | nucleic acid |
| | B) | amino acid |
| | C) | pentose sugar |
| | D) | protein |
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22 | | All of the following are functions of the Golgi complex except |
| | A) | preparing new proteins for inside-the-cell use. |
| | B) | further modification of new proteins (for example glycoproteins or glycolipids). |
| | C) | organizing proteins by function and destination. |
| | D) | packaging the final proteins and shipping to their destination. |
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23 | | Capsases are |
| | A) | enzymes that are inactivated during apoptosis. |
| | B) | enzymes that become activated when the mitochondria become "leaky." |
| | C) | regulators of the cell cycle. |
| | D) | regulators of necrosis. |
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24 | | Cytokinesis occurs during |
| | A) | prophase. |
| | B) | metaphase. |
| | C) | anaphase. |
| | D) | telophase. |
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25 | | The phase of the cell cycle during which DNA replicates itself is known as ____ phase. |
| | A) | G2 |
| | B) | G1 |
| | C) | S |
| | D) | M |
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26 | | One very important tumor suppressor gene that has been found to be mutated in more than 50% of all cancers is known as |
| | A) | an oncogene. |
| | B) | a centromere. |
| | C) | p53. |
| | D) | cyclin D. |
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27 | | The concentration of cyclin D proteins within the cell rise and act to move the cell quickly through the ____ phase of the cell's cycle. |
| | A) | G1 |
| | B) | S |
| | C) | G2 |
| | D) | M |
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28 | | Centrioles |
| | A) | replicate during prophase of a dividing cell. |
| | B) | are DNA sequences that act as caps on the end of genes. |
| | C) | are comprised of microfilaments. |
| | D) | interact with spindle fibers to assist in moving chromosomes during mitosis. |
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29 | | Spindle fibers attach to the _____ on each chromosome during mitosis. |
| | A) | kinetochore |
| | B) | chromosome |
| | C) | centromere |
| | D) | centriole |
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30 | | Which of the following share identical base sequences? |
| | A) | two homologous chromosomes |
| | B) | two chromatids |
| | C) | DNA transcribed to mRNA |
| | D) | mRNA translated to tRNA |
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31 | | Which of the following statements about meiosis is false? |
| | A) | Each daughter cell is genetically identical to the parent cell. |
| | B) | Final daughter cells are gametes, either four sperm or a single ova. |
| | C) | Each daughter cell contains a total of twenty-three chromosomes (haploid). |
| | D) | Crossing-over or mixing of maternal and paternal chromosomes may occur. |
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32 | | Which of the following events only occurs during meiosis and not in mitosis? |
| | A) | metaphase I |
| | B) | anaphase I |
| | C) | cytokinesis |
| | D) | crossing over |
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33 | | A transporter protein in the plasma membrane would be an example of which type of protein? |
| | A) | cytosolic |
| | B) | peripheral |
| | C) | lateral |
| | D) | integral |
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34 | | Which of the following processes involve the extension of pseudopods? |
| | A) | phagocytosis |
| | B) | endocytosis |
| | C) | exocytosis |
| | D) | receptor-mediated endocytosis |
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35 | | The mechanism whereby some viruses, including the AIDS and polio viruses, enter cells is called |
| | A) | phagocytosis. |
| | B) | endocytosis. |
| | C) | exocytosis. |
| | D) | receptor-mediated endocytosis. |
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36 | | Which of the following molecules cannot pass through nuclear pores? |
| | A) | water |
| | B) | potassium ions |
| | C) | glycerol |
| | D) | DNA |
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37 | | What characteristic of embryonic stem cells distinguishes them from other types of stem cells? |
| | A) | They differentiate into other types of cells earlier than other stems cells. |
| | B) | They can differentiate into more types of cells than other stem cells. |
| | C) | Cells differentiated from embryonic stem cells continually divide. |
| | D) | They are easier to obtain than other types of stem cells. |
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38 | | In terms of telomerase, cancer cells are most like which of the following cell types? |
| | A) | muscle cells |
| | B) | red blood cells |
| | C) | germinal cells |
| | D) | cartilage cells |
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