Correct Answer: (c)
Heartwood differs from sapwood in having dead and non-conducting elements. In old trees, the inner region that comprises dead elements with highly lignified walls is called heartwood.
Q2. Which one of the following is wrongly matched?
[2011]
Correct Answer: (b)
Puccinia causes Rust disease. Smut is a disease of cereals, corn, grasses and sorghum caused by many species of fungi (Ustilago).
Q3. At maturity which of the following is enucleate?
[1997]
Correct Answer: (a)
Sieve tubes members do not have ribosomes or a nucleus and thus need companion cells to help them function as transport molecules.
Q4. A narrow layer of thin walled cells found between phloem/bark and wood of a dicot is
[1993]
Correct Answer: (b)
Vascular cambium is produced by two types of meristems, fascicular and interfascicular cambium.
Q5. Organisation of stem apex into corpus and tunica is determined mainly by
[1989]
Correct Answer: (a)
Cells of tunica divide anticlinally to form the outer layer, cells of corpus undergo division in different planes.
Q6. Identify the incorrect statement.
[2020]
Correct Answer: (b)
Correct statement: Sapwood is outermost secondary xylem. Outer secondary xylem or sapwood serves in water conduction, while the inner part called heartwood is composed of dead but structurally strong primary xylem.
Q7. Which of the following facilitates opening of stomatal aperture?
[2017]
Correct Answer: (b)
Cellulose microfibrils are arranged radially rather than longitudinally which makes easy for the stomata to open.
Q8. The vascular cambium normally gives rise to:
[2017]
Correct Answer: (b)
During secondary growth in plants vascular cambium gives rise to secondary xylem and secondary phloem. Phelloderm is formed by cork cambium. Periderm is the corky outer layer formed in secondary thickening.
Q9. Tracheids differ from other tracheary elements in:
[2014]
Correct Answer: (b)
The walls of vessels (tracheary elements) are lignified and less thicker than tracheids. The lumen is wider. Vessels differ from tracheids in having cell fusions arising through the dissolution of end walls (perforated), whereas tracheids are imperforate (no perforations).
Q10. You are given a fairly old piece of dicot stem and a dicot root. Which of the following anatomical structures will you use to distinguish between the two?
[2014]
Correct Answer: (c)
Anatomically fairly old dicotyledonous root is distinguished from the dicotyledonous stem by position of the protoxylem. In dicot root, the protoxylem is located near the periphery of the vascular cylinder while in dicot stem the protoxylem is located near the centre of vascular bundle i.e. the xylem is endarch.
Q11. Regeneration of damaged growing grass following grazing is largely due to:
[2019]
Correct Answer: (d)
Intercalary meristems are capable of cell division and they allow for rapid growth and regrowth of many monocots. Intercalary meristem, found in grasses, help to regenerate the parts removed by the grazing herbivores.
Q12. Vascular cambium produces
[1990, 92]
Correct Answer: (b)
Vascular cambium produces secondary xylem on the inner side and secondary phloem to the outer side.
Q13. Collenchyma occurs in the stem and petioles of
[1990]
Correct Answer: (c)
Collenchyma provides mechanical strength to young dicot stems, petioles and leaves.
Q14. Collenchyma occurs in
[1990]
Correct Answer: (c)
Collenchyma is abundant in climbing stems providing mechanical strength.
Q15. Age of a tree can be estimated by :
[NEET 2013]
Correct Answer: (b)
Age of a tree can be estimated by number of annual rings. Annual ring constitute alternate concentric rings of spring wood and autumn wood.
Q16. Vessels are found in
[2002]
Correct Answer: (b)
Generally gymnosperms do not have vessels but a few gymnosperms with vessels are Ephedra, Smilax etc. Most of angiosperms have vessels except few e.g., Trochodendron.
Q17. The chief water conducting elements of xylem in gymnosperms are:
[2010]
Correct Answer: (d)
Tracheids are chief water conducting elements of xylem in gymnosperms. They are devoid of protoplasm and hence dead.
Q18. Secondary xylem and phloem in dicot stem are produced by
[2018]
Correct Answer: (b)
The vascular cambium produces secondary xylem on the inside of the ring, and secondary phloem on the outside, pushing the primary xylem and phloem apart. The vascular cambium usually consists of two types of cells: Fusiform initials (tall, axially oriented) Ray initials (smaller and round to angular in shape)
Q19. The apical meristem of the root is present
[2003]
Correct Answer: (a)
The apical meristem of the root is present at all the root tips. Apical meristem is subterminal in position of the growing root tips and responsible for terminal growth of the root in plants.
Q20. In land plants, the guard cells differ from other epidermal cells in having :
[2011]
Correct Answer: (d)
Guard cells differ from epidermal cells in having chloroplast. The cell wall of guard cells are not uniform, inner walls are thicker than the outer walls, epidermal cells are thicker than the inner walls.
Q21. The cork cambium, cork and secondary cortex are collectively called:
[2011]
Correct Answer: (c)
Phellem, phellogen and phelloderm are collectively called periderm.
Q22. Lenticels are involved in :
[NEET 2013]
Correct Answer: (a)
Lenticels are lens shaped openings occuring in stems of most of the woody trees. It permits the exchange of gases between the outer atmosphere and the internal tissue of the stem.
Q23. What happens during vascularization in plants?
[2000]
Correct Answer: (b)
Vascularization of plant means the development of vascular bundle in the plant, which develop from the cambium.
Q24. Bordered pits are found in
[1993]
Correct Answer: (b)
The walls of xylem vessels are lignified and bordered pits are common in the walls.
Q25. Vascular bundles in monocotyledons are considered closed because:
[2015 RS]
Correct Answer: (a)
Vascular bundles in monocotyledons are considered closed due to absence of cambium.
Q26. The annular and spirally thickened conducting elements generally develop in the protoxylem when the root or stem is:
[2009]
Correct Answer: (d)
The annular and spirally thickened conducting elements generally develop in the protoxylem when the root or stem is maturing.
Q27. Which of the following is made up of dead cells?
[2017]
Correct Answer: (b)
Cork cambium undergoes periclinal division and cuts off thick walled suberised dead cells towards outside i.e. phellem (cork) and it cuts off thin walled living cells i.e., phelloderm on inner side.
Q28. Procambium forms
[1994]
Correct Answer: (a)
Procambium is the derivative of shoot apical meristem and forms vascular strand.
Q29. Which of the following meristems is responsible for extrastelar secondary growth in dicotyledonous stem?
[1998]
Correct Answer: (d)
Intrafascicular cambium occurs inside the vascular bundles in between xylem and phloem. Interfascicular cambium develops in the form of strips at the level of intrafascicular cambium of vascular bundles. Intercalary meristem lie in between areas of permanent tissues.
Q30. The common bottle cork is a product of :
[2012]
Correct Answer: (b)
The common bottle cork is the product of phellogen. Phellogen produces cork or phellem on the outer side. It consists of dead and compactly arranged rectangular cells that possess suberised cell walls.
Q31. In the dicot root the vascular cambium originates from :
[2019, Odisa]
Correct Answer: (b)
Vascular cambium is a secondary meristematic tissue, in dicot roots. It is originated from tissue located below the phloem bundles and a portion of pericycle tissue above the protoxylem.
Q32. Water containing cavities in vascular bundles are found in :
[2012]
Correct Answer: (b)
Stem of maize has water containing cavities in vascular bundles.
Q33. Tunica corpus theory is connected with
[1988]
Correct Answer: (c)
The shoot apex or stem apical meristem has two zones, outer tunica and inner corpus. This theory was given by Schmidt 1924.
Q34. A common structural feature of vessel elements and sieve tube elements are
[2006]
Correct Answer: (c)
In plants, conducting tissue xylem has an important integral cell as xylem vessel which is enucleate. The phloem on other hand has a row of sieve tubes which are also enucleate at maturity.
Q35. Closed vascular bundles lack
[2012]
Correct Answer: (c)
In closed vascular bundle cambium is absent between xylem and phloem.
Q36. Some vascular bundles are described as open because these
[2011M]
Correct Answer: (b)
Open vascular bundles means presence of cambium during secondary growth. Vascular cambium divides to form secondary xylem towards inner side while secondary phloem towards outside.
Q37. Periderm is produced by
[1993]
Correct Answer: (c)
Secondary ground tissue or periderm is formed from phellogen or cork cambium. The phellogen forms phellem on the outer face and phelloderm on the inner side. The three layers i.e., phellem, phellogen and phelloderm jointly constitute the periderm.
Q38. Chlorenchyma is known to develop in the
[2003]
Correct Answer: (d)
Chlorenchyma cells are those parenchymatous cell which contain chloroplast in them. They are capable of photosynthesis. A spore capsule of moss can perform photosynthesis, thus chlorenchyma are present in them.
Q39. A bicollateral vascular bundle is characterised by
[1992]
Correct Answer: (d)
Bicollateral vascular bundles have phloem in both outer and inner side of xylem. These type of bundles occur in cucurbitaceae.
Q40. Transition of radial vascular bundle in root to conjoint vascular bundle in stem occurs in which zone?
[1999]
Correct Answer: (b)
Transition of radial vascular bundle in root to conjoint vascular bundle in stem occurs in transition zone which is generally hypocotyl. Hypocotyl is the part of embryonal axis below the level of cotyledons.
Q41. Transmission tissue is characteristic feature of:
[2015 RS]
Correct Answer: (a)
A solid style has transmission tissue which has large intercellular spaces. It allows growth of pollen tube in pistil.
Q42. For a critical study of secondary growth in plants. Which one of the following pairs is suitable?
[2007]
Correct Answer: (a)
Teak and pine are most suitable for the study of critical secondary growth because in secondary growth, secondary tissues are formed from lateral meristem which is well developed in two cases and secondary growth occurs in gymnosperms and dicots.
Q43. Which is the correct fact about diffuse or ring porous wood?
[1989]
Correct Answer: (c)
Ring porous wood is more advanced than diffuse porous wood as it provides for better translocation when requirement of plant is high.
Q44. In a longitudinal section of a root, starting from the tip upward, the four zones occur in the following order:
[2004]
Correct Answer: (a)
Root shows the following regions: Root cap or calyptra -> Meristematic region -> Zone of elongation -> Root hair zone/Zone of maturation.
Q45. Read the different components from (a) to (D) in the list given below and tell the correct order of the components with reference to their arrangement from outer side to inner side in a woody dicot stem. (A) Secondary cortex (B) Wood (C) Secondary phloem (D) Phellem The correct order is:
[2015 RS]
Correct Answer: (b)
The correct sequence from outerside to inner side in a woody dicot stem is as follows: Phellem -> Secondary cortex -> Secondary phloem -> Wood , [(D) -> (A) -> (C) -> (B)]
Q46. Vascular tissues in flowering plants develop from:
[2008]
Correct Answer: (b)
Vascular tissues in flowering plants develop from plerome. Plerome is a central core of primary meristem which gives rise to all cells of the stele from the pericycle inward.
Q47. Ground tissue includes
[2011]
Correct Answer: (b)
Ground tissue includes all tissues except epidermis and vascular bundles. The ground tissue comprises the bulk of the primary plant body. Parenchyma, collenchyma and sclerenchyma cells are common in the ground tissue.
Q48. Passage cells are thin walled cells found in
[2007]
Correct Answer: (d)
The innermost layer of the cortex is called endodermis. It comprises a single layer of barrel shaped cells without any intercellular spaces. In roots thick walled endodermal cells are interrupted by thin walled passage cells or transfusion tissue.
Q49. What is not true about sclereids?
[1996]
Correct Answer: (a)
Sclereids are small bundles of sclerenchyma tissue in plants that form durable layers, not parenchyma.
Q50. Companion cells are closely associated with:
[2012]
Correct Answer: (a)
Companion cells are narrow, elongated and thin walled living cells. They lie on the sides of the sieve tubes and are closely associated with them through compound plasmodesmata.
Q51. Cork cambium and vascular cambium are
[1990, 95]
Correct Answer: (c)
Cork cambium and vascular cambium are responsible for secondary growth which increases the girth of the stem.
Q52. Gymnosperms are also called soft wood spermatophytes because they lack :
[2012]
Correct Answer: (d)
Xylem fibres provide rigidity to the plant.
Q53. Commercial cork is obtained from
[1991]
Correct Answer: (c)
Quercus suber (cork oak or bottle cork) possess cork cells. Cork cells are dead, suberized and impervious to water and air, compactly arranged with no intercellular spaces.
Q54. Sieve tubes are suited for translocation of food because they possess
[1989]
Correct Answer: (c)
Sieve tubes are elongated tubular conducting channels of phloem. The end walls possess many small pores and have thin cellulosic wall. The lumen is broad in nature.
Q55. The length of different internodes in a culm of sugarcane is variable because of
[2008]
Correct Answer: (d)
The length of different internodes in a culm of sugarcane is variable because of intercalary meristem. Intercalary meristem is not a part of apical meristem. It occurs in the internodes of grasses (sugarcane) between leaf nodes and enables longitudinal growth of the stem.
Q56. Pith and cortex do not differentiate in
[1988]
Correct Answer: (a)
The ground tissue in monocot stem do not show distinction into cortex, endodermis, pericycle, pith and pith rays.
Q57. Plant having column of vascular tissues bearing fruits and having a tap root system is
[1994]
Correct Answer: (b)
Dicots possess tap root system.
Q58. Abnormal/anomalous secondary growth occurs in
[1993]
Correct Answer: (a)
Abnormal secondary growth occurs in some arborescent monocots (eg. : Dracaena, Yucca)
Q59. Anatomically fairly old dicotyledonous root is distinguished from the dicotyledonous stem by
[2009]
Correct Answer: (c)
Anatomically fairly old dicotyledonous root is distinguished from the dicotyledonous stem by position of protoxylem. In dicot root the protoxylem is located near the periphery of the vascular cylinder while in dicot stem the protoxylem is located near the centre of vascular bundle i.e. the xylem is endarch.
Q60. What is true about a monocot leaf?
[1990]
Correct Answer: (c)
In monocot leaves, the mesophyll cells are undifferentiated.
Q61. Main function of lenticel is
[2002]
Correct Answer: (a)
Lenticels are pores present in woody stem through which transpiration or loss of water vapour takes place. Lenticel formation begins during the development of the first periderm.
Q62. Which one of the following is resistant to enzyme action?
[2008]
Correct Answer: (c)
Pollen exine is resistant to enzyme action. The hard outer layer called the exine is made up of sporopollenin which is one of the most resistant organic material known. It can withstand high temperatures and strong acids and alkali. No enzymes that degrade sporopollenin are so far known.
Q63. Which of the statements given below is not true about formation of annual rings in trees?
[2019]
Correct Answer: (d)
Growth rings are formed by the seasonal activity of cambium. In plants of temperate regions, cambium is more active in spring (less lignin deposition in xylem) and less active in autumn (more lignin deposition in xylem) seasons. In temperate regions climatic conditions are not uniform throughout the year. However in tropics climatic conditions are uniform throughout the year.
Q64. Ectophloic siphonostele is found in
[2004]
Correct Answer: (a)
The central pith is surrounded by xylem, phloem, pericycle and endodermis . The phloem occurs only outside the xylem e.g Equisetum, Osmunda.
Q65. Interfascicular cambium develops from the cells of :
[NEET 2013]
Correct Answer: (d)
At the time of secondary growth interfascicular cambium is formed by parenchymatous medullary rays.
Q66. An organised and differentiated cellular structure having cytoplasm but no nucleus is
[1991]
Correct Answer: (c)
Internally, sieve tubes possess peripheral layer of cytoplasm and are devoid of nucleus.
Q67. Which one yields fibres?
[1988]
Correct Answer: (a)
Commercial fibres are obtained from Cocos nucifera (coconut) also called surface fibres and occur on surface of seeds.
Q68. Function of companion cells is
[2011M]
Correct Answer: (d)
Function of companion cell is to load sugar and amino acids into sieve elements. These cells use transmembrane proteins for uptake by active transport.
Q69. For union between stock and scion in grafting which one is the first to occur?
[1990]
Correct Answer: (a)
In grafting, union between stock and scion produces undifferentiated mass of cells called callus.
Q70. The transverse section of a plant shows following anatomical features : (i) Large number of scattered vascular bundles surrounded by bundle sheath (ii) Large conspicuous parenchymatous ground tissue (iii) Vascular bundles conjoint and closed (iv) Phloem parenchyma absent Identify the category of plant and its part :
[2020]
Correct Answer: (d)
The monocot stem is characterised by conjoint, collateral, and closed vascular bundles, scattered in the ground tissue containing the parenchyma. Each vascular bundle is surrounded by sclerenchymatous bundle-sheath cells. Phloem parenchyma and medullary rays are absent in monocot stems.
Q71. The roots that originate from the base of the stem are
[2020]
Correct Answer: (d)
Xylem formation begins when the actively dividing cells of growing root and shoot tips (apical meristems) give rise to primary xylem. The roots that originate from the base of the stem are fibrous roots.
Q72. Palisade parenchyma is absent in leaves of:
[2009]
Correct Answer: (d)
Palisade parenchyma is absent in leaves of sorghum (Monocot). It is a leaf tissue composed of columnar cells containing numerous chloroplasts in which the long axis of each cell is perpendicular to the leaf surface. The palisade parenchyma is usually directly beneath the epidermis of the upper surface of the leaf.
Q73. In barley stem vascular bundles are:
[2009]
Correct Answer: (a)
In barley stem, vascular bundles are closed and scattered. They are open only for a hours in the day time and never open at night. e.g Cereals.
Q74. A major characteristic of the monocot root is the presence of :
[2015 RS]
Correct Answer: (b)
Secondary tissues are generated from the growth of a cambium. Vascular cambium gives rise to secondary xylem to the inside, and to secondary phloem to the outside. Monocot root shows radial and closed vascular bundle (xylem & phloem).
Q75. Monocot leaves possess
[1990]
Correct Answer: (a)
Intercalary meristems are derived from apical meristems and separated from the same by permanent cells. They are responsible for localised growth.
Q76. Identify the wrong statement in context of heartwood:
[2017]
Correct Answer: (b)
Heartwood is inactive physiologically due to deposition of organic compounds and formation of tyloses so it will not conduct water and minerals.
Q77. Pericycle of roots produces
[1990]
Correct Answer: (b)
Pericycle in roots is active in the formation of root branches or lateral roots.
Q78. The cells of the quiescent centre are characterised by
[2003]
Correct Answer: (c)
The cells of quiescent centre have lower concentration of DNA, RNA and protein as compared to other cells in the root apex. These cells do not divide, hence cytoplasm is light and nuclei are small in them.
Q79. In a woody dicotyledonous tree, which of the following parts will mainly consist of primary tissues?
[2005]
Correct Answer: (d)
Primary Meristems : They are those meristematic tissues which are dervied directly from the meristems of the embryo and retain their meristematic activity. They are present at root, shoot tip and leaf primordia.
Q80. Cork is formed from
[1988]
Correct Answer: (a)
Phellogen present in outer cortical cells produce cork or phellem on the outer side which consists of dead and compactly arranged rectangular cells that possess suberised cell walls which causes them to become buoyant. Phellogen also cuts off cells on innerside called as phelloderm or secondary cortex.
Q81. Casparian strips occur in
[2018]
Correct Answer: (c)
Casparian strip is a band of cell wall material deposited in the radial and transverse walls of the endodermis. Casparian strip is made of suberin and sometimes lignin.
Q82. Xylem translocates:
[2019]
Correct Answer: (d)
Xylem is a type of complex tissue. It translocates water, mineral salts, organic nitrogen and hormones.
Q83. Which one of the following is not a lateral meristem?
[2010]
Correct Answer: (d)
Meristem is divided on the basis of position in plant bodies into apical meristem, lateral meristem and intercalary meristem. Lateral meristem is present on the lateral sides, that is fascicular and interfascicular cambium and cork cambium (phellogen).
Q84. Loading of pholem is related to
[2001]
Correct Answer: (a)
Phloem is involved in transport of organic food. According to mass flow hypothesis organic substances flow in the form of solution in sieve elements due to development of an osmotically generated pressure gradient.
Q85. Four radial vascular bundles are found in
[2002]
Correct Answer: (a)
When xylem and phloem strands are present at different radii the vascular bundles are radial and 4 radial vascular bu ndles (tetrach condition) are present in dicot root. This is called tetrach conditions.
Q86. A leaf primordium grows into the adult leaf lamina by means of
[1998]
Correct Answer: (d)
A leaf primordium grows into the adult leaf lamina by means of apical meristem first and later marginal meristems.
Q87. Which of the following statements is true?
[2002]
Correct Answer: (d)
Vessels are elongated, multicellular water conducting channels with wide lumen formed by end to end fusion of a large number of vessel elements. Tracheids are elongated dead cells with tapering ends having lignified walls and large or wide lumen. (Note: Key accepts d).
Q88. Which meristem helps in increasing girth?
[1988]
Correct Answer: (a)
Lateral meristems occur on the sides of stem and help in increasing girth of stem and root. It divides only periclinally or radially and is responsible for increase in girth or diameter.
Q89. In a ring girdled plant:
[2015 RS]
Correct Answer: (a)
In a ring girdled plant, roots die first due to damage of phloem causing inhibition of translocation of food.
Q90. Axillary bud and terminal bud are derived from the activity of
[2002]
Correct Answer: (c)
Apical meristem is located at the apex of stem, root and branches, and forms axillary and terminal bud.
Q91. As the secondary growth takes place (proceeds) in a tree, thickness of
[1994]
Correct Answer: (a)
Heartwood is the central wood of mature dicot stem and is the nonfunctional part of secondary xylem.
Q92. Where do the casparian bands occur?
[1990, 94]
Correct Answer: (b)
Endodermis or innermost layer of cortex has casparian strips in roots. It is called starch sheath in dicot stems. It separates cortex from stele. The cell walls are thickened at the corners in angular collenchyma.
Q93. Which exposed wood will decay faster?
[1993]
Correct Answer: (a)
Sapwood is less durable because it is susceptible to attack by pathogen and insects. It is physiologically active and conduction of water takes place through it. Heartwood is not attacked by pathogens and insects as it is physiologically inactive. It is filled with tannins, resins and gums which are not preferred by insects and pathogens.
Q94. Root hairs develop from the region of :
[2017]
Correct Answer: (d)
In roots, the root hairs develops from zone of maturation. This zone is differentiated zone thus bearing root hairs.
Q95. Which of the following statements is not true for stomatal apparatus?
[NEET Kar. 2013]
Correct Answer: (c)
Sometimes, a few epidermal cells in the vicinity of the guard cells become specialised in their shape and size and are known as subsidiary cells or accessory cells. (Not always).
Q96. Reduction in vascular tissue, mechanical tissue and cuticle is characteristic of:
[2009]
Correct Answer: (c)
Reduction in vascular tissue, mechanical tissue and cuticle is characteristic of hydrophytes.
Q97. Angular collenchyma occurs in
[1991]
Correct Answer: (a)
Along with providing mechanical strength, collenchyma also provides flexibility to the organ and allows their bending eg. : Cucurbita.
Q98. Meristematic tissue responsible for increase in girth of tree trunk is
[NEET Kar. 2013]
Correct Answer: (c)
Lateral meristems are meristems which occur parallel to the circumference of the organs in which they develop. They undergo periclinal divisions producing secondary tissues on the outer and inner sides and increase the girth of the plant organs.
Q99. Plants having little or no secondary growth are
[2018]
Correct Answer: (a)
Grasses are monocots and monocots usually do not have secondary growth. Palm like monocots have anomalous secondary growth.
Q100. As compared to a dicot root, a monocot root has
[2012M]
Correct Answer: (a)
The vascular bundles are arranged in a loose circle inside the endodermis of a monocot root. In a monocot root, more than six vascular bundles are present. It shows polyarch condition.
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