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4

In stems, the protoxylem lies towards the _____________ and the metaxylem lies towards the ____________ of the organ.

A. centre; periphery

B. periphery; centre

C. periphery; periphery

D. centre; centre

Correct Answer :

A. centre; periphery


The first formed primary xylem elements are called protoxylem and the later formed primary xylem is called metaxylem. In stems, the protoxylem lies towards the centre (pith) and the metaxylem lies towards the periphery of the organ. This type of primary xylem is called endarch.

Related Questions

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4

Gymnosperms are also called soft wood spermatophytes because they lack

A. cambium

B. phloem fibres

C. thick-walled tracheids

D. xylem fibres

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4

A plant tissue when stained showed the presence of hemicellulose and pectin in cells wall of its cells. The tissue is called

A. collenchyma

B. sclerenchyma

C. xylem

D. meristem

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4

A narrow layer of thin walled cells found between phloem/ bark and wood of a dicot is

A. cork cambium

B. vascular cambium

C. endodermis

D. both (a) & (c)

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4

Match column-I with column-II and choose the correct option.
Column -IColumn -II
A. Bulliform cellsI. Initiation of lateral roots
B. PericycleII. Root
C. Endarch xylemIII. Grasses
D. Exarch xylemIV. Dicot leaf
E. Bundle sheath cellsV. Stem

A. A III, B V, C IV, D I, E II

B. A II, B V, C I, D III, E IV

C. A II, B IV, C I, D III, E V

D. A III, B I, C V, D II, E IV

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4

Match column-I with column-II and choose the correct option.
A. Spring wood orI. Lighter in colour early wood
B. Autumn wood orII. High density late wood
..III. Low density
..IV. Darker in colour
..V. Larger number of xylem elements
..VI. Vessels with wider cavity
..VII. Lesser number of xylem elements
..VIII. Vessels with small cavity

Which of the following combination is correct ?

A. A II, IV, VII, VIII; B I, III, V, VI

B. A I, II, VII, VIII; B III, IV, V, VI

C. A I, III, V, VI; B II, IV, VII, VIII

D. A I, III, VII, VIII; B II, IV, V, VI

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4

Identify types of vascular bundles in given figures A, B and C.

A. Radial; Conjoint closed; Conjoint open

B. Conjoint closed; Conjoint open; Radial

C. Conjoint open; Conjoint closed; Radial

D. Bicollateral; Concentric; Radial

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4

Match the followings and choose the correct option
Column-IColumn-II
A. CuticleI. Guard cells
B. Bulliform cellsII. Outer layer
C. StomataIII. Waxy layer
D. EpidermisIV. Empty colourless cell

A. A III, B IV, C I, D II

B. A I, B II, C III, D IV

C. A III, B II, C IV, D I

D. A III, B II, C I, D IV

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4

Which of the following statement(s) is/are not correct?
  1. Cork cambium is also called phellogen.
  2. Cork is also called phellem.
  3. Secondary cortex is also called periderm.
  4. Cork cambium, cork and secondary cortex are collectively called phelloderm.

A. (iii) and (iv)

B. (i) and (ii)

C. (ii) and (iii)

D. (ii) and (iv)

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4

The apical meristem of the root is present

A. in all the roots.

B. only in radicals.

C. only in tap roots.

D. only in adventitious roots.

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4

Phellogen and phellem respectively denote

A. cork and cork cambium,

B. cork cambium and cork,

C. secondary cortex and cork,

D. cork and secondary cortex,

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4

The vessel elements of angiosperms differ from other elements of xylem in having

A. simple pits on their radial walls.

B. bordered pits on their lateral walls.

C. simple and bordered pits on their end walls.

D. simple perforation on their end walls.

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4

As secondary growth proceeds, in a dicot stem, the thickness of

A. sapwood increases.

B. heartwood increase.

C. both sapwood and heartwood increases.

D. both sapwood and heartwood remains the same.

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4

Which one of the following statement is incorrect ?
  1. Epidermal cell has small amount of cytoplasm and a large vacuole.
  2. Waxy cuticle layer is absent in roots.
  3. Root hairs are unicellular, while stem hairs / trichomes are multicellular.
  4. Trichomes may be branched or unbranched, soft or stiff and prevent transpiration.
  5. Guard cells are dumbell shaped in dicots and beanshaped in monocots (e.g. grass).

A. Only (i)

B. Only (iv)

C. Only (iii)

D. Only (v)

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4

Which type of plant tissue is being described by the given statements?
  1. It consists of long, narrow cells with thick and lignified cell walls having a few or numerous pits.
  2. They are dead and without protoplasts.
  3. On the basis of variation in form, structure, origin and development, it may be either fibres or sclereids.
  4. It provides mechanical support to organs.

A. Parenchyma

B. Sclerenchyma

C. Collenchyma

D. Chlorenchyma

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4

Main function of lenticel is

A. transpiration

B. guttation

C. gaseous exchange

D. both (a) & (c)

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4

The trees growing in desert will

A. show alternate rings of xylem and sclerenchyma.

B. have only conjunctive tissue and phloem is formed by the activity of cambium.

C. show distinct annual rings.

D. not show distinct annual rings.

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4

The given figures are types of elements (A and B) which constitute one type of complex tissue (c) of a plant . Identify A, B and C.

A. A Tracheid, B Vessel, C Xylem

B. A Vessel, B Tracheild, C Phloem

C. A Fibre, B Tracheid, C Bark

D. A Fibre, B Sclereid, C Casparian strips

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4

Which of the following is responsible for the formation of an embryonic shoot called axillary bud?

A. Lateral meristem

B. Apical meristem

C. Intercalary meristem

D. Both

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4

Various functions like photosynthesis, storage, excretion performed by _____________.

A. sclerenchyma

B. parenchyma

C. collenchyma

D. aerenchyma

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4

During the formation of leaves and elongation of stem, some cells left behind from the shoot apical meristem, constitute the

A. lateral meristem

B. axillary bud

C. cork cambium

D. fascicular cambium

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4

Xylem functions as a conducting tissue for water and minerals from _________to the ______and__________.

A. roots, stems, leaves

B. stems, roots, leaves

C. leaves, stems, roots

D. leaves, stems, leaves

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4

Sclerenchyma usually___________and_____________ protoplasts.

A. live, without

B. dead, with

C. live, with

D. dead, without

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4

Which one of the following have vessels as their characteristic feature?

A. Angiosperms

B. Gymnosperms

C. Pteridophytes

D. Bryophytes

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4

In land plants, the guard cells differ from other epidermal cells in having

A. cytoskeleton.

B. mitochondria.

C. endoplasmic reticulum.

D. chloroplasts.

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4

Tissue(s) present in an annual ring is/are

A. secondary xylem and phloem.

B. primary xylem and phloem.

C. secondary xylem only.

D. primary phloem and secondary xylem.

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4

Sieve tubes are suited for translocation of food because they possess

A. bordered pits.

B. no ends walls.

C. broader lumen and perforated cross walls.

D. no protoplasm.

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4

Which of the following statements is correct?

A. Lenticels occur in most woody trees.

B. Sclerenchymatous cells are usually present in cortex.

C. The vascular tissue system is divided into three main zones- cortex, pericycle and pith.

D. The conjoint vascular bundles usually have the xylem located only on the outer side of the phloem.

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4

A vascular bundle in which the protoxylem is pointing to the periphery is called __________.

A. endarch

B. exarch

C. radial

D. closed

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4

Apical, intercalary and lateral meristems are differentiated on the basis of

A. origin

B. function

C. position

D. development

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4

Which of the following pair of match is not correct?

A. Pith - Large and well developed in monocotyledonous root.

B. Root hairs - Helps in preventing water loss due to transpiration

C. Sieve tube elements - Its functions are controlled by the nucleus of companion cells.

D. Stomatal apparatus - Consists of stomatal aperture, guard cells and surrounding subsidiary cells