Tag: internal structure of root, stem and leaf
Questions Related to internal structure of root, stem and leaf
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Stems and roots of dicots
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Stems and roots of gymnosperms
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Stems and roots of monocots
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Both (b) and (c)
Stems of monocots do not have lateral or secondary cambium. Roots of both monocots and dicots do not have secondary or lateral cambium. Hence, true secondary growth does not occur in stems and roots of monocots. But, in some exceptional cases if secondary growth takes place due to dedifferentiation of tissue cells of the cortex, pericycle etc into meristematic tissue this type of secondary growth is called anomalous secondary growth.
The lacunae in the vascular bundles of monocot stem is
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A mucilage canal
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Protoxylem lacuna
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Lysigenous cavity
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Both B and C
The first xylem formed is called as protoxylem. Protoxylem is later torn apart and a cavity is formed. The entire protoxylem is dissolved hence, such cavity is called as lysigenous cavity. The protoxylem shows an empty space, called as 'lacuna'.
Transverse section of a material exhibits conjoint collateral endarch and closed bundles scattered in a ground tissue, what should be the material?
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Monocot root
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Dicot root
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Monocot stem
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Dicot stem
Monocot stem vascular bundles are found irregularly scattered in the ground tissue.
T.S. of a material exhibits conjoint collateral endarch and closed bundles scattered in a ground tissue. What should be the material?
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Monocot root
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Dicot root
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Monocot stem
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Dicot stem
Monocot stem vascular bundles are found irregularly scattered in the ground tissue. Towards the periphery, the bundles are smaller in size while towards the centre, they are larger in size. The smaller bundles are younger, while the larger ones are older. Hence, the arrangement is described as endarch.
Atactostele is found in
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Dicot stem
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Monocot stem
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Dicot root
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Monocot root
Monocot stems, in which the stele consists of many vascular bundles in a complex arrangement, are said to have an atactostele.
Stem of date palm increases in girth due to activity of:
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Intercalary meristem
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Apical meristem
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Lateral meristem
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None of the above
Date palm is a monocot and lack lateral meristem; the meristem present along the sides causing the increase in girth of the plant.
Lysigenous cavity and 'Y'-shaped xylem occurs in
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Dicot stem
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Monocot root
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Monocot stem
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Dicot root
Lysigenous intercellular spaces is type of intercellular space arises through dissolution of entire cells, which are therefore called as lysigenous cavity. These cavities of intercellular spaces store up water, gases and essential oils in them. The examples are commonly found in water plants and many monocotyledonous stems. The secretory cavities in Eucalyptus, Citrus and Gossypium are good examples. In monocot stem the vascular bundle encloses both xylem and phloem. Xylem is found towards the inner surface and phloem towards the outer surface. Cambium is absent. Hence, the vascular bundles are described as conjoint, collateral and closed. In the xylem, there are two metaxylem and two protoxylem vessels arranged in the shape of Y.
Endodermis is not differentiated in which of the following
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Monocot root
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Dicot root
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Monocot stem
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Dicot stem
In monocot stem, cortex is not differentiated into hypodermis, general cortex and endodermis. In the place of cortex a large, wide region is present called Ground tissue is present. It is parenchymatous, stores water and food materials. In this vascular bundles are present scatteredly.
So, the correct option is ‘monocot stem’
Fibrovascular bundles or vascular bundles covered by sclerenchymatous sheath are found in
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Monocot leaf
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Monoct stem
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Monocot root
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Dicot stem
A.Monocot leaf – vascular bundles are covered by parenchymatous bundle sheath.
B. Monocot stem – vascular bundles are covered by sclerenchymatous fibres. So these are called fibrovascular bundles.
C. Monocot root – there is no any covering around the vascular bundles.
D. Dicot stem – there is no any covering around the vascular bundles.
So, the correct option is ‘Monocot stem’.
Phloem parenchyma is absent in
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Dicot root
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Dicot leaf
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Monocot stem
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Dicot stem
A.Dicot root – phloem parenchyma is present.
B.Dicot leaf – Phloem parenchyma is present.
C.Monocot stem – phloem parenchyma is absent.
D.Dicot stem – Phloem parenchyma is present.
So, the correct answer is 'Monocot stem'.