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These are the answers to the quiz.
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1) Tracheids have been shortened during evolution. They are only found in gymnosperms.
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| Not answered. It is false. Tracheids are also found in angiosperms, although they are less abundant than in gymnosperms. |
2) Annular and reticular thickenings of the cell wall of tracheae are features of the protoxylem.
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| Not asnwered. It is false. Reticular thickenings may be present in the metaxylem, but are characteristics of the secondary xylem.
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3) Water travels via symplast through the lateral areolate pits of tracheae, but mostly travels through the perforated plates of the transverse cell walls.
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| Not answered. It is true. |
4) The main force propelling water along the xylem is the root water pressure.
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| Not asnwered. It is false. The main driven force that moves water in the xylem is transpiration. |
5) The mature conducting elements of the xylem are cells with thick cell walls and without cytoplasm.
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| Not answered. It is true. Although xylem parenchyma cells show living cytoplasm, they are not conducting cells. |
6) The sieve elements loose their nucleus during differentiation.
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| Not answered. It is true. Sieve elements lose their nucleus during maturation. However, they keep part of the cytoplasm, known as protoplasm. |
7) Sieve elements communicate between each other only by pit fields know as sieve plates.
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| Not answered. It is false. Sieve elements have also pit areas in their lateral walls that communicate neighbor cells. |
8) The main role of albuminiferous and associated cells is to provide physical support to the phloem tissue.
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| Not answered. It is false. Both cell types mainly perform metabolic functions. |
9) Sieve cells are the only conducting element in the phloem of gymnosperms.
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| Not answered. It is true. |
10) During secondary growth, protophloem and protoxylem are replaced by secondary phloem and secondary xylem.
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| Not answered. It is false. Secondary phloem substitutes metaphloem, but no protophloem. Likewise, secondary xylem substitutes metaxylem, not protoxylem. |
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Click the images to enlarge
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F-1) Asterisks indicate the metaxylem tracheae.
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Not answered. It is true.
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F-2) Labels are correctly placed.
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Not answered. It is false. the correct labelling is in the second image.
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Results
Total of valid answers = 12
Right answers = 0
Wrong answers = 0
Not answered = 12
Unusefull answers = 0
The score of the quiz (range between 0 and 10) = 0,0 Do you need to read the descriptive pages again ?
