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These are the answers to the quiz.
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1) Meristematic cells do not contain many free ribosomes but a highly developed endoplasmic reticulum needed for protein synthesis.
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| Not amswered. It is false. Proteins are synthesized by ribosomes, but most proteins in plant tissues are intracellular proteins, so the endoplasmic reticulum is not as well-developed in plant cells as in animal cells. |
2) Meristematic cells show a small nucleus with condensed chromatin.
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| Not answered. It is false. Although with a high proportion of condensed chromatin, meristematic cells contain a large nucleus found in a central position. |
3) Primary meristems are found at the tips of stems and roots, as well as in the internode regions of the stems.
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| Not answered. It is true. Primary meristems are found at the apex of shoots and roots, where they are responsible for growing in length. The so-called intercalary meristems are found in the internode regions of stems. They are regarded as primary meristems and produce growth in length too. |
4) During the primary growth, the cork cambium meristem produces cork toward the outer part of the organ (root or stem) by periclinal divisions.
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| Not answered. It is false. During the primary growth of stems and roots, there is no cork cambium. Cork cambium is observed in plants with secondary growth. |
5) The initial cells are meristematic cells with the ability of dedifferentiation.
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| Not answered. It is false. Although the initial cells are meristematic cells, they are already undifferentiated cells. Thus, they cannot dedifferentiate. |
6) The periclinal division plane is parallel to the surface of the organ and leads to the enlargement of the girth.
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| Not answered. It is true. |
7) The procambium meristem generates vascular cambium, which produces secondary xylem and phloem.
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| Not answered. It is true. |
8) The shoot apical meristems are found in a sub-apical position (not at the tip) because they are protected by the leaf primordia.
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| Not answered. It is false. Although apical meristems are protected by the leaf primordia, the apical shoot meristems are found at the very tip of the stems. |
9) The main part of the growing in length of stems is produced by the intercalary meristems, found at the internode region.
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| Not answered. It is true. |
10) Statocysts are cells of the calyptra of the root that sense gravity and direct the root to grow toward the center of the earth.
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| Not answered. It is true. Statocysts contain amyloplasts with high content of starch that are involved in sensing gravity and therefore in the direction of the growing of the root. |
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Click the images to enlarge
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F-1) The dots indicate the proliferation region of the primary root.
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Not answered. It is false. The dots indicate the root cap.
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F-2) The dots enclose the interfascicular parenchyma.
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Not answered. It is false. The dots enclose the phloem.
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F-3) This image shows an apical caulinar meristem protected by the leaf primordia.
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Not answered. It is true.
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F-4) The dots enclose the cork cambium.
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Not answered. It is true.
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