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1 | | A cell can be divided into three principal parts: the cell (plasma) membrane, the cytoplasm and organelles, and the nucleus. |
| | A) | True |
| | B) | False |
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2 | | The cell membrane is also known as the plasma membrane. |
| | A) | True |
| | B) | False |
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3 | | The cytoplasm is the fluid portion of the cytosol. |
| | A) | True |
| | B) | False |
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4 | | The membrane is not solid, the phospholipid and protein molecules are free to move laterally in a constantly changing mosaic pattern—often referred to as the fluid-mosaic model of membrane structure. |
| | A) | True |
| | B) | False |
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5 | | The uptake of cholesterol molecules by cells lining an arterial blood vessel is an example of endocytosis. |
| | A) | True |
| | B) | False |
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6 | | In the process of endocytosis, secretory vesicles fuse with the cell membrane and release their contents into the extracellular environment. |
| | A) | True |
| | B) | False |
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7 | | In the human body, cilia are found along the basal surface of epithelial cells (the surface facing the lumen, or cavity) of the respiratory and female reproductive tracts. |
| | A) | True |
| | B) | False |
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8 | | In the human body, cilia and flagella are composed of protein microtubules arranged in a characteristic "9 + 2" pattern. |
| | A) | True |
| | B) | False |
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9 | | The jellylike matrix within a cell is known as the cytoskeleton. |
| | A) | True |
| | B) | False |
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10 | | The cytoskeleton is composed of protein fibers called microtubules and microfilaments, arranged in a complex flexible and mobile latticework. |
| | A) | True |
| | B) | False |
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11 | | Autophagy is a process involving lysosomes that destroy worn-out organelles so that they can be continuously replaced—also characterized as the "digestive system" of the cell. |
| | A) | True |
| | B) | False |
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12 | | Many more mitochondria are found in the ovum (egg cell) compared to sperm; and contain a more primitive form of DNA molecules that can transmit genetic defects from mother to child. |
| | A) | True |
| | B) | False |
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13 | | Most, if not all, organelles in the cell have a limited life span, and thus must be continuously destroyed and replaced. |
| | A) | True |
| | B) | False |
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14 | | Smooth endoplasmic reticulum would be abundant in cells that are active in protein synthesis and secretion, such as those of many exocrine and endocrine glands. |
| | A) | True |
| | B) | False |
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15 | | The phenomenon of "tolerance" to certain substances such as alcohol and certain drugs may be accompanied by increased amounts of the rough endoplasmic reticulum, particularly in liver cells. |
| | A) | True |
| | B) | False |
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16 | | Mitochondria may be able to reproduce themselves, especially in cells that require greater than normal energy outputs. |
| | A) | True |
| | B) | False |
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17 | | Small molecules may pass through the nuclear pore complexes located along the nuclear envelope by simple diffusion, but movement of larger protein and RNA molecules is a selective, energy-requiring process. |
| | A) | True |
| | B) | False |
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18 | | The expression of genes occurs in two sequential stages: first, genetic transcription and then, genetic translation. |
| | A) | True |
| | B) | False |
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19 | | Nucleoli are dark regions within the nucleus that contain DNA and code for the production of ribosomal RNA (rRNA). |
| | A) | True |
| | B) | False |
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20 | | Although DNA is the largest molecule in the cell, it has a simpler structure than that of most proteins. |
| | A) | True |
| | B) | False |
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21 | | According to the law of complementary base pairing, the number of purine bases in DNA molecules is greater than the number of pyrimidine bases in DNA. |
| | A) | True |
| | B) | False |
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22 | | Although composed of only four different types of bases, a gene extends several thousand nucleotides in length. |
| | A) | True |
| | B) | False |
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23 | | DNA is double-stranded helix, meaning there are two chains of DNA that twist about one another to form a molecule resembling a spiral staircase. |
| | A) | True |
| | B) | False |
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24 | | DNA strands spool around negatively charged histone proteins in the nucleus to form larger chromatin particles called nucleosomes. |
| | A) | True |
| | B) | False |
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25 | | Acetylation of chromatin is necessary for inactivating transcription by compacting the chromatin. |
| | A) | True |
| | B) | False |
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26 | | All types of RNA are formed from the information contained in the DNA within the nucleus. |
| | A) | True |
| | B) | False |
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27 | | Like DNA, RNA is also double-stranded. |
| | A) | True |
| | B) | False |
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28 | | The synthesis of RNA molecules from DNA is called genetic translation. |
| | A) | True |
| | B) | False |
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29 | | In the synthesis of RNA, the enzyme RNA polymerase is required to "unzip" a section of the paired DNA bases by breaking the weak hydrogen bonds and transcribing only one exposed strand of DNA. |
| | A) | True |
| | B) | False |
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30 | | The genes from DNA in the nucleolus located within the nucleus of the cell code for the specific production of transfer RNA (tRNA). |
| | A) | True |
| | B) | False |
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31 | | In humans, a pre-tRNA is produced that must be modified within the nucleus before it can enter the cytoplasm as tRNA and direct protein synthesis. |
| | A) | True |
| | B) | False |
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32 | | Segments of DNA scattered along a gene that do not participate in transcription of the genetic code, are called introns |
| | A) | True |
| | B) | False |
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33 | | Arriving in the cytoplasm, the mRNA can pass through a number of ribosomes to form a "string-of-pearls" structure called a polyribosome, or polysome, for short. |
| | A) | True |
| | B) | False |
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34 | | The sequence of three bases (a base triplet) in mRNA is called a codon, while the complementary triplet in tRNA is called an anticodon. |
| | A) | True |
| | B) | False |
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35 | | Proteins that are to be used within the cell are produced by the polyribosomes that float freely in the cytoplasm region of the cell. |
| | A) | True |
| | B) | False |
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36 | | Proteins that are synthesized for specific functions within a particular cell possess a hydrophobic leader sequence that permits the entry of these proteins into the cisterna of the rough endoplasmic reticulum. |
| | A) | True |
| | B) | False |
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37 | | A stack of several flattened sacs that receive, modify, and repackage proteins into new vesicles best describes the endoplasmic reticulum of the cell. |
| | A) | True |
| | B) | False |
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38 | | "Semiconservative" means only one of the two DNA strands is needed to synthesize pre-mRNA during transcription. |
| | A) | True |
| | B) | False |
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39 | | DNA helicase is responsible for unwinding the DNA molecule prior to DNA replication. |
| | A) | True |
| | B) | False |
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40 | | The non-dividing cell exists in a part of its life cycle known as interphase—which is subdivided into G1, S, and G2 phases. |
| | A) | True |
| | B) | False |
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41 | | The "S" phase of the cell cycle refers to the secretory phase of the cell. |
| | A) | True |
| | B) | False |
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42 | | A group of proteins known as the cyclins are active during different phases of the cell cycle. |
| | A) | True |
| | B) | False |
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43 | | Apoptosis refers to cell death during which the cell swells, ruptures its membranes, and burst. |
| | A) | True |
| | B) | False |
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44 | | Necrosis refers to cell death during which the cell swells, ruptures its membranes, and burst. |
| | A) | True |
| | B) | False |
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45 | | Capsases are enzymes that when activated stimulate apoptosis within a cell. |
| | A) | True |
| | B) | False |
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46 | | At the end of the G2 phase of the cell cycle, each chromosome consists of two strands called chromatids which are joined together by a centromere. |
| | A) | True |
| | B) | False |
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47 | | In anaphase of mitosis, the chromosomes line up single file along the equator of the cell. |
| | A) | True |
| | B) | False |
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48 | | The division of the cytoplasm during telophase is called cytokinesis. |
| | A) | True |
| | B) | False |
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49 | | During mitosis, the centrosomes organize contractile filaments that consist of actin and myosin that attach to the cell membrane and help pinch the mother cell into two identical daughter cells. |
| | A) | True |
| | B) | False |
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50 | | Growth due to an increase in cell number as a result of mitotic cell division is called hypertrophy. |
| | A) | True |
| | B) | False |
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51 | | Polycythemia is defined as an abnormal increase in the number of circulating red blood cells and therefore would be an example of hypertrophy. |
| | A) | True |
| | B) | False |
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52 | | Meiosis is also known as reduction division since the daughter cells contain twenty-three rather than forty-six chromosomes. |
| | A) | True |
| | B) | False |
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