1. Study of plant tissues is called ____________.
A) Histology
B) Cytology
C) Morphology
D) Taxonomy
Answer: A
Explanation: Histology deals with microscopic study of tissues.
2. Plant tissues are broadly classified into ____________.
A) Xylem and phloem
B) Meristematic and permanent
C) Simple and complex
D) Collenchyma and sclerenchyma
Answer: B
Explanation: This is the fundamental classification.
3. Meristematic tissues are characterized by ____________.
A) Thin walls, dense cytoplasm, no vacuoles
B) Thick walls, dead cells
C) Lignified cells
D) Large vacuoles
Answer: A
Explanation: Meristematic tissues are the “growth engines” of a plant. Because these cells are constantly dividing to create new organs and extend the plant’s length, their structure is optimized for rapid metabolism and cell division rather than storage or structural support.
4. Meristematic tissues are responsible for ____________.
A) Photosynthesis
B) Growth in plants
C) Water conduction
D) Food conduction
Answer: B
Explanation: Meristematic tissues are essentially the “growth engines” of a plant. They consist of actively dividing cells that facilitate the development of new organs and the overall expansion of the plant body.
5. Apical meristems occur at ____________.
A) Tips of root and shoot
B) Base of stem
C) In between permanent tissue
D) In leaves only
Answer: A
Explanation: Responsible for primary growth.
6. Intercalary meristem is found at ____________.
A) Node and base of internode
B) Root tip
C) Leaf apex
D) Stem apex only
Answer: A
Explanation: Found in grasses, responsible for regrowth after grazing.
7. Lateral meristems are responsible for ____________.
A) Primary growth
B) Secondary growth
C) Root elongation
D) Leaf fall
Answer: B
Explanation: lateral meristems are responsible for making the plant thicker. This increase in the diameter or “girth” of the plant’s stems and roots is known as secondary growth.
8. Vascular cambium and cork cambium are examples of ____________.
A) Apical meristem
B) Intercalary meristem
C) Lateral meristem
D) Permanent tissue
Answer: C
Explanation: Vascular cambium and cork cambium are both examples of lateral meristems. These tissues are found on the lateral sides of stems and roots and are responsible for the increase in thickness or girth of the plant.
9. Which meristem is responsible for increase in thickness of stem/root?
A) Apical meristem
B) Lateral meristem
C) Intercalary meristem
D) None
Answer: B
Explanation: Lateral meristems are specifically designed to increase the thickness, diameter, or girth of a plant’s stem and roots. This process is known as secondary growth.
10. Permanent tissues originate from ____________.
A) Apical meristem
B) Lateral meristem
C) Differentiation of meristematic cells
D) Root hairs
Answer: C
Explanation: Permanent tissues are formed when the cells produced by meristematic tissues stop dividing and undergo a process called differentiation.
11. Dedifferentiation is ____________.
A) Conversion of permanent tissue into meristematic tissue
B) Conversion of meristematic into permanent
C) Cell death
D) Photosynthesis in parenchyma
Answer: A
Explanation: Dedifferentiation is a fascinating biological “reversal” where mature, specialized cells regain the ability to divide.
12. Redifferentiation means ____________.
A) Permanent tissue → Meristematic
B) Meristematic → Permanent tissue with specific function
C) Cell death
D) Mutation in tissue
Answer: B
Explanation: Redifferentiation is the final stage in a remarkable three-step cycle that allows plants to grow in thickness and heal themselves.
13. Meristematic cells divide by ____________.
A) Meiosis
B) Mitosis
C) Amitosis
D) Both mitosis and meiosis
Answer: B
Explanation: Meristematic cells are the primary growth tissue in plants. To facilitate growth, they must produce more cells that are genetically identical to the original, which is the specific function of mitosis.
14. Root apical meristem is protected by ____________.
A) Root cap
B) Root hair
C) Cork
D) Pericycle
Answer: A
Explanation: The root apical meristem is a very delicate region of actively dividing cells. Because roots must push through abrasive soil particles to grow, they require a specialized “shield” to prevent damage to these growth cells.
15. Shoot apical meristem is protected by ____________.
A) Leaf primordia
B) Root cap
C) Cork
D) Cotyledons
Answer: A
Explanation: the Root Apical Meristem (RAM) has a specialized, cap-like structure (the root cap) to push through soil, the Shoot Apical Meristem (SAM) is protected by leaf primordia.
16. Cells of meristematic tissue contain ____________.
A) Dense cytoplasm and prominent nucleus
B) Large vacuoles
C) Dead protoplasm
D) Lignified walls
Answer: A
Explanation: Meristematic cells are optimized for rapid and continuous cell division. Their internal structure reflects this high metabolic state, focusing all cellular resources on the machinery needed for mitosis.
17. The term “meristem” was coined by ____________.
A) Hanstein
B) Strasburger
C) Haberlandt
D) Carl Wilhelm von Nägeli
Answer: D
Explanation: The term “meristem” was coined by the Swiss botanist Carl Wilhelm von Nägeli in 1858
18. Pericycle shows ____________.
A) Primary growth
B) Secondary growth in roots
C) Photosynthesis
D) Storage of food
Answer: B
Explanation: The pericycle is a unique, pluripotent layer of cells located just inside the endodermis.
19. Cork cambium produces ____________.
A) Xylem and phloem
B) Cork cells and secondary cortex
C) Pith
D) Endodermis
Answer: B
Explanation: The cork cambium, also known as phellogen, is a lateral meristem responsible for the secondary growth that creates the protective outer covering of woody plants.
20. Xylem and phloem are produced by ____________.
A) Apical meristem
B) Intercalary meristem
C) Vascular cambium
D) Cork cambium
Answer: C
Explanation: The vascular cambium is a thin layer of meristematic cells located between the xylem and phloem.
21. Meristematic tissues are absent in ____________.
A) Animals
B) Plants
C) Fungi
D) Bacteria
Answer: A
Explanation: Meristematic tissue is a specialized type of tissue found exclusively in plants. While all the organisms listed grow and develop, they do so using different cellular mechanisms.
22. Interfascicular cambium is ____________.
A) Primary meristem
B) Secondary meristem
C) Permanent tissue
D) None
Answer: B
Explanation: Interfascicular cambium is a perfect example of how plants can “reactivate” mature cells to allow for further growth.
23. Apical dominance in plants is due to ____________.
A) Cytokinins
B) Gibberellins
C) Auxins
D) Abscisic acid
Answer: C
Explanation: Apical dominance is a phenomenon where the main, central stem of a plant grows more vigorously than the side (lateral) branches. This happens because the shoot tip (apex) produces hormones that suppress the growth of nearby buds.
24. Example of intercalary meristem ____________.
A) Sugarcane
B) Pea
C) Mango
D) Mustard
Answer: A
Explanation: Intercalary meristems are specifically found in monocots, particularly in members of the grass family (Poaceae). They are located at the base of internodes or leaf blades.
25. Which statement is NOT true about meristematic tissues?
A) Cells have dense cytoplasm
B) Cells divide actively
C) Cells are dead
D) Cells lack vacuoles
Answer: C
Explanation: Meristematic tissues are composed of living cells. Because their primary role is to divide and grow continuously, they must be highly active metabolically.
26. Permanent tissues are formed by ____________.
A) Meristematic cells differentiating
B) Root hairs
C) Cork cambium only
D) Dead xylem
Answer: A
Explanation: Meristematic cells stop dividing and become specialized permanent tissues.
27. Permanent tissues are of how many main types?
A) One
B) Two
C) Three
D) Four
Answer: C
Explanation: (i) Simple, (ii) Complex, (iii) Special/secretory.
28. Which of the following is a simple permanent tissue?
A) Xylem
B) Phloem
C) Parenchyma
D) Cambium
Answer: C
Explanation: Simple permanent tissues are called “simple” because they are composed of only one type of cell that is structurally and functionally similar. Parenchyma: The most common tissue, composed of living, thin-walled cells. They are responsible for photosynthesis, storage, and wound healing.
29. Parenchyma cells are usually ____________.
A) Dead, lignified
B) Living, thin-walled
C) Thick-walled and dead
D) Dead with pits
Answer: B
Explanation: Parenchyma cells have thin cellulose walls, store food, and can photosynthesize.
30. Parenchyma with chloroplasts is called ____________.
A) Collenchyma
B) Aerenchyma
C) Chlorenchyma
D) Sclerenchyma
Answer: C
Explanation: Chlorenchyma is a specialized type of parenchyma that contains chlorophyll (housed within chloroplasts). Because of these chloroplasts, the primary function of chlorenchyma is photosynthesis.
31. Parenchyma with large air spaces is called ____________.
A) Collenchyma
B) Aerenchyma
C) Chlorenchyma
D) Sclerenchyma
Answer: B
Explanation: Aerenchyma helps in buoyancy in aquatic plants.
32. Which simple permanent tissue provides mechanical support and flexibility?
A) Parenchyma
B) Collenchyma
C) Sclerenchyma
D) Phloem
Answer: B
Explanation: Collenchyma is a living simple permanent tissue that acts as a “living mechanical tissue.” It is uniquely designed to provide both structural strength and elasticity to the plant.
33. Cell wall thickening in collenchyma is due to ____________.
A) Lignin
B) Cellulose and pectin
C) Suberin
D) Chitin
Answer: B
Explanation: Collenchyma is a living mechanical tissue, and its unique ability to provide both strength and flexibility is a direct result of its cell wall composition.
34. Sclerenchyma cells are ____________.
A) Living with thin walls
B) Dead with lignified thick walls
C) Dead with thin walls
D) Living with chloroplasts
Answer: B
Explanation: Sclerenchyma is the primary mechanical tissue of mature plant parts.
35. Two types of sclerenchyma cells are ____________.
A) Tracheids and vessels
B) Fibres and sclereids
C) Parenchyma and collenchyma
D) Cambium and phloem
Answer: B
Explanation: Sclerenchyma is a simple permanent tissue characterized by dead cells with highly thickened, lignified walls. Based on their shape, structure, and origin.
36. Coconut husk is composed of ____________.
A) Parenchyma
B) Collenchyma
C) Sclerenchyma fibres
D) Xylem
Answer: C
Explanation: The coconut husk (the fibrous mesocarp) is a classic example of sclerenchyma tissue. Specifically, it is made of long, narrow sclerenchyma fibres that provide the extreme toughness and rigidity needed to protect the seed inside during long periods of floating in seawater.
37. Gritty texture in guava/pear is due to ____________.
A) Fibres
B) Sclereids (stone cells)
C) Parenchyma
D) Collenchyma
Answer: B
Explanation: The “gritty” or sandy sensation you feel when eating a pear or guava is caused by small clusters of sclereids, also known as stone cells. These are a specialized type of sclerenchyma cell.
38. Which of the following is a complex permanent tissue?
A) Parenchyma
B) Collenchyma
C) Xylem
D) Sclerenchyma
Answer: C
Explanation: Xylem is classified as a complex permanent tissue because it is made up of more than one type of cell that work together as a single unit to perform a common function—the conduction of water and minerals.
39. Xylem is mainly responsible for ____________.
A) Transport of food
B) Transport of water and minerals
C) Photosynthesis
D) Secretion
Answer: B
Explanation: Xylem is the specialized vascular tissue in plants responsible for the “upward” conduction of water and dissolved inorganic minerals.
40. Phloem is mainly responsible for ____________.
A) Transport of water
B) Transport of food
C) Transport of minerals
D) Storage of starch
Answer: B
Explanation: Phloem is the living vascular tissue responsible for the translocation of organic nutrients—primarily sucrose—produced during photosynthesis.
41. The four elements of xylem are ____________.
A) Tracheids, vessels, xylem parenchyma, xylem fibres
B) Sieve tubes, companion cells, phloem fibres, phloem parenchyma
C) Parenchyma, collenchyma, sclerenchyma, fibres
D) Cambium, cork, cortex, pith
Answer: A
Explanation: Xylem is a complex permanent tissue, which means it is composed of different types of cells that work together to perform a single function—transporting water and providing mechanical support.
42. The chief water-conducting element in angiosperms is ____________.
A) Tracheids
B) Vessels
C) Fibres
D) Phloem
Answer: B
Explanation: vessels (also known as vessel elements) are considered the chief or primary water-conducting elements in angiosperms (flowering plants).
43. The chief water-conducting element in gymnosperms is ____________.
A) Tracheids
B) Vessels
C) Fibres
D) Parenchyma
Answer: A
Explanation: In gymnosperms (non-flowering plants like pines, cedars, and firs), tracheids are the primary cells responsible for the transport of water and minerals.
44. Xylem parenchyma is ____________.
A) Dead
B) Living
C) Lignified
D) Mechanical only
Answer: B
Explanation: Xylem parenchyma stores food and assists in lateral conduction.
45. Which xylem element is absent in most gymnosperms?
A) Tracheids
B) Vessels
C) Fibres
D) Parenchyma
Answer: B
Explanation: In most gymnosperms (like pines and cedars), the xylem is considered “non-porous” because it lacks vessels.Instead, they rely almost entirely on tracheids for water conduction.
46. The elements of phloem are ____________.
A) Sieve tubes, companion cells, phloem fibres, phloem parenchyma
B) Tracheids, vessels, fibres, parenchyma
C) Cambium, cork, pith, cortex
D) Guard cells, epidermis, cork, sclereids
Answer: A
Explanation: Phloem is a complex permanent tissue found in vascular plants. It acts as the plant’s “delivery system,” transporting organic nutrients (mainly sucrose) from the leaves to the roots, fruits, and growing buds.
47. Sieve tubes are living because ____________.
A) They have nuclei
B) They are supported by companion cells
C) They are lignified
D) They contain chloroplasts
Answer: B
Explanation: Sieve tubes are unique because they are living cells without a nucleus at maturity. To stay alive and function despite lacking a nucleus and ribosomes, they rely entirely on their “neighbors”—the companion cells.
48. Phloem fibres are ____________.
A) Living
B) Dead
C) Photosynthetic
D) Storage cells
Answer: B
Explanation: Phloem fibres (bast fibres) are elongated, lignified, and used in jute.
49. Which phloem element is absent in gymnosperms?
A) Phloem parenchyma
B) Companion cells
C) Sieve cells
D) Fibres
Answer: B
Explanation: Gymnosperms have sieve cells instead of sieve tubes and lack companion cells.
50. Bast fibres are obtained from ____________.
A) Phloem
B) Xylem
C) Pith
D) Cortex
Answer: A
Explanation: Phloem fibres provide commercial fibres like jute, flax, hemp.
51. The outermost protective layer in young plant parts is ____________.
A) Cortex
B) Epidermis
C) Pericycle
D) Endodermis
Answer: B
Explanation: Epidermis is a single cell layer providing protection.
52. Cuticle on epidermis is made of ____________.
A) Lignin
B) Cutin (waxy substance)
C) Suberin
D) Pectin
Answer: B
Explanation: Prevents water loss and provides protection.
53. Small pores on epidermis for gaseous exchange are ____________.
A) Lenticels
B) Stomata
C) Hydathodes
D) Trichomes
Answer: B
Explanation: Stomata are microscopic openings or pores found in the epidermis of leaves and young stems. They are the primary site for gaseous exchange and the regulation of water loss in plants.
54. Guard cells controlling stomatal opening are ____________.
A) Living
B) Dead
C) Lignified
D) Non-functional
Answer: A
Explanation: Guard cells must be living to function because the opening and closing of stomata is an active physiological process that requires energy (ATP) and metabolic activity.
55. Trichomes are ____________.
A) Root hairs
B) Epidermal outgrowths
C) Xylem elements
D) Phloem fibres
Answer: B
Explanation: They reduce transpiration and protect from herbivores.
56. The main tissue of cortex is ____________.
A) Collenchyma
B) Parenchyma
C) Sclerenchyma
D) Phloem
Answer: B
Explanation: The cortex is a primary region of ground tissue located between the epidermis (outer layer) and the vascular bundles (xylem and phloem). While other tissues can be present, the vast majority of the cortex is composed of parenchyma cells.
57. The innermost layer of cortex is ____________.
A) Endodermis
B) Pericycle
C) Phloem
D) Cambium
Answer: A
Explanation: It regulates flow of water and minerals into vascular tissues.
58. Casparian strips in endodermis are made of ____________.
A) Lignin
B) Cutin
C) Suberin
D) Pectin
Answer: C
Explanation: Casparian strips are specialized, waterproof bands located in the endodermis (the innermost layer of the root cortex). Their primary function is to regulate the flow of water and dissolved minerals from the soil into the vascular cylinder.
59. Pericycle is located ____________.
A) Inside epidermis
B) Inside endodermis, around vascular bundles
C) Around pith
D) Around cuticle
Answer: B
Explanation: The pericycle is a unique layer of cells that marks the outermost boundary of the stele (the central vascular cylinder) in both roots and stems.
60. In dicot stem, vascular bundles are ____________.
A) Scattered
B) In a ring
C) Absent
D) In parallel rows
Answer: B
Explanation: Helps in secondary growth.
61. In monocot stem, vascular bundles are ____________.
A) Scattered
B) In a ring
C) Absent
D) Radial
Answer: A
Explanation: Monocot stems lack cambium and secondary growth.
62. Vascular bundles in dicot stem are ____________.
A) Open and collateral
B) Closed and collateral
C) Radial
D) Conjoint and closed
Answer: A
Explanation: Open bundles have cambium (allowing secondary growth).
63. Vascular bundles in monocot stem are ____________.
A) Open
B) Closed
C) With cambium
D) In a ring
Answer: B
Explanation: No cambium, hence no secondary growth.
64. Pith is prominent in ____________.
A) Dicot stem
B) Monocot stem
C) Dicot root
D) Monocot root
Answer: A
Explanation: Dicot Stem is the primary intended answer because the pith is a defining central feature of its ring-like vascular arrangement.
65. Pith is absent or reduced in ____________.
A) Dicot stem
B) Monocot stem
C) Dicot leaf
D) Monocot leaf
Answer: B
Explanation: In a monocot stem, the pith is considered absent or reduced because the ground tissue is not differentiated into distinct regions like the cortex, pericycle, and pith.
66. Vascular bundles in dicot root are ____________.
A) 2–6 (polyarch)
B) Many (polyarch)
C) Scattered
D) Concentric
Answer: A
Explanation: In a dicot root, the number of vascular bundles (xylem and phloem patches) is limited, typically ranging from two to six.
67. Vascular bundles in monocot root are ____________.
A) 2–6 (diarch to hexarch)
B) Many (polyarch)
C) Scattered
D) Concentric
Answer: B
Explanation: monocot roots usually have more than six, a condition known as polyarch.
68. Exarch xylem condition is found in ____________.
A) Stem
B) Root
C) Leaf
D) Pith
Answer: B
Explanation: In exarch, protoxylem lies towards periphery (common in roots).
69. Endarch xylem condition is found in ____________.
A) Root
B) Stem
C) Leaf
D) Pericycle
Answer: B
Explanation: In endarch, protoxylem lies towards centre (stems).
70. Secondary growth is present in ____________.
A) Dicot stem and root
B) Monocot stem and root
C) Leaf only
D) All plants equally
Answer: A
Explanation: Secondary growth is the process by which a plant increases in girth or thickness (rather than height). It is a characteristic feature of dicots and gymnosperms, but it is typically absent in monocots.
71. Secondary growth is absent in ____________.
A) Dicot stem
B) Dicot root
C) Monocot stem
D) Dicot leaf
Answer: C
Explanation: Secondary growth is the process that increases the girth or thickness of a plant. While this is a standard feature of most dicot stems, dicot roots, and gymnosperms, it is characteristically absent in monocots (like maize, wheat, and grasses).
72. In dicot root, vascular bundles are arranged ____________.
A) Scattered
B) Radially
C) In ring
D) Concentric
Answer: B
Explanation: In all roots (both dicot and monocot), the vascular bundles are arranged in a radial pattern.This means that the xylem and phloem are not joined together in a single bundle.
73. In dicot stem, vascular bundles are arranged ____________.
A) Scattered
B) Radially
C) In ring (collateral, open)
D) Polyarch
Answer: C
Explanation: In a dicot stem, the vascular bundles are arranged in a highly organized ring-like pattern around a central pith.
74. In leaf, vascular bundles are ____________.
A) Collateral and closed
B) Radial
C) Open
D) Concentric
Answer: A
Explanation: Vascular bundles in leaves lack cambium, hence no secondary growth.
75. Bulliform cells are present in ____________.
A) Dicot leaf
B) Monocot leaf (upper epidermis)
C) Root epidermis
D) Stem cortex
Answer: B
Explanation: Bulliform cells help in rolling and unrolling of monocot leaves.
76. Growth in girth of dicot stems is due to activity of ____________.
A) Apical meristem
B) Vascular cambium and cork cambium
C) Pericycle
D) Phloem
Answer: B
Explanation: Both lateral meristems bring about secondary growth.
77. Annual rings in woody plants are formed due to ____________.
A) Apical meristem activity
B) Secondary xylem formed by vascular cambium
C) Cork cambium activity
D) Pith parenchyma
Answer: B
Explanation: Annual rings (also known as growth rings) are the visible results of secondary growth in trees. They are essentially layers of secondary xylem (wood) produced by the vascular cambium over the course of a single growing season.
78. Heartwood differs from sapwood in ____________.
A) Function
B) Colour
C) Hardness
D) All of these
Answer: D
Explanation: Heartwood is darker, non-functional, lignified; sapwood is lighter and functional.
79. Lenticels are involved in ____________.
A) Transpiration
B) Secondary growth
C) Gaseous exchange in woody stems
D) Food conduction
Answer: C
Explanation: Lenticels are specialized, lens-shaped pores found in the bark or periderm of woody stems and roots. They act as “breathing pores” for the plant, particularly after the epidermis has been replaced by bark.
80. Periderm consists of ____________.
A) Epidermis
B) Cork cambium, cork, and secondary cortex
C) Pith, cortex, phloem
D) Xylem and phloem
Answer: B
Explanation: The periderm is the protective tissue system that replaces the epidermis in woody stems and roots as they undergo secondary growth.
81. Bark of a tree is ____________.
A) Only cork
B) All tissues outside vascular cambium
C) Only phloem
D) Xylem and phloem together
Answer: B
Explanation: In botany, bark is a broad, non-technical term used to describe every layer of tissue located external to the vascular cambium in a woody stem or root.
82. Early wood is ____________.
A) Formed in spring, less dense, larger vessels
B) Formed in winter, dense and narrow vessels
C) Formed in root apex
D) Dead part of xylem
Answer: A
Explanation: Early wood, also known as spring wood, is the layer of wood produced by a tree during the early part of the growing season (usually spring).
83. Late wood is ____________.
A) Formed in summer/winter, dense with thick-walled vessels
B) Formed in spring
C) Found in pith
D) Dead cortex
Answer: A
Explanation: Late wood, also known as autumn wood, is the layer of secondary xylem produced towards the end of the growing season.
84. Sapwood is also called ____________.
A) Active xylem
B) Dead xylem
C) Periderm
D) Phellem
Answer: A
Explanation: Sapwood is the peripheral (outer) region of the secondary xylem in a woody plant. It is biologically “active” because it contains living parenchyma cells and is the primary tissue responsible for the conduction of water and minerals from the roots to the leaves.
85. Heartwood is also called ____________.
A) Active wood
B) Dead, non-functional wood
C) Pericycle
D) Cambial wood
Answer: B
Explanation: In a mature woody tree, the center of the trunk is occupied by heartwood, which is the older, inner layer of secondary xylem. It is technically “dead” because its cells are no longer involved in the transport of water or nutrients.
86. Cork cells are ____________.
A) Living, thin-walled
B) Dead, suberized, protective
C) Lignified, dead
D) Photosynthetic
Answer: B
Explanation: Cork cells (technically called phellem) are the outermost layer of the periderm in woody plants. They are produced by the cork cambium to replace the epidermis as the plant grows in girth.
87. Which tissue is also known as bast fibres?
A) Xylem fibres
B) Phloem fibres
C) Collenchyma
D) Sclereids
Answer: B
Explanation: Phloem fibres are also known as bast fibres. These are sclerenchymatous cells found in the phloem tissue (usually the secondary phloem) that provide mechanical strength to the plant.
88. The commercial fibre jute is obtained from ____________.
A) Phloem of stem
B) Xylem of root
C) Leaf mesophyll
D) Pith of stem
Answer: A
Explanation: Jute is a bast fibre, which means it is derived from the secondary phloem (the “inner bark”) of the plant’s stem. Specifically, it is obtained from the species Corchorus olitorius and Corchorus capsularis.
89. Cork cambium is also known as ____________.
A) Phellogen
B) Phellem
C) Phelloderm
D) Endodermis
Answer: A
Explanation: The cork cambium is a lateral meristematic tissue responsible for secondary growth in the cortical region of the plant.
90. Cork is also known as ____________.
A) Phellogen
B) Phellem
C) Phelloderm
D) Cambium
Answer: B
Explanation: “cork” is the tissue that forms on the outer surface of a woody plant’s stem or root to replace the epidermis. It is specifically referred to as phellem.
91. Secondary cortex produced by cork cambium is called ____________.
A) Phellogen
B) Phellem
C) Phelloderm
D) Endodermis
Answer: C
Explanation: The secondary cortex is a living tissue layer produced on the inner side of the cork cambium during secondary growth. It is composed of thin-walled parenchyma cells that often look quite similar to the primary cortex cells.
92. The function of pericycle in roots is ____________.
A) Primary growth
B) Origin of lateral roots
C) Photosynthesis
D) Secondary thickening only
Answer: B
Explanation: The pericycle is a unique layer of cells located just inside the endodermis of the root.Its most critical and universal function across all vascular plants is the initiation of lateral (side) roots.
93. Which plant shows anomalous secondary growth?
A) Sunflower
B) Maize
C) Dracaena
D) Mustard
Answer: C
Explanation: Secondary growth in monocots like Dracaena is abnormal.
94. Secondary xylem forms towards ____________.
A) Outside
B) Inside
C) Pericycle
D) Cork
Answer: B
Explanation: Secondary Xylem (Wood): Formed towards the inside (towards the pith or center of the stem).
95. Secondary phloem forms towards ____________.
A) Inside
B) Outside
C) Pith
D) Medullary rays
Answer: B
Explanation: Secondary Phloem: Produced towards the outside (towards the periphery or bark).
96. Wood is actually ____________.
A) Xylem
B) Phloem
C) Cambium
D) Cortex
Answer: A
Explanation: “wood” is the common name for secondary xylem. It is the complex, fibrous tissue produced by the vascular cambium during the secondary growth of dicot stems and roots.
97. The annual rings are useful in ____________.
A) Identifying plant family
B) Age determination of plant
C) Photosynthesis
D) Storage of food
Answer: B
Explanation: Annual rings (also called growth rings) are concentric layers of secondary xylem that appear in the cross-section of a woody stem or root.
98. Which one of the following is NOT a complex tissue?
A) Xylem
B) Phloem
C) Cambium
D) None
Answer: C
Explanation: Cambium is meristematic, not a permanent complex tissue.
99. What is the main function of companion cells in phloem?
A) Provide mechanical support
B) Assist sieve tube elements in translocation of food
C) Store starch
D) Help in transpiration
Answer: B
Explanation: Companion cells are specialized parenchyma cells that act as a “life-support system” for sieve tube elements in the phloem of angiosperms. They are essential because mature sieve tube elements lack a nucleus, ribosomes, and most organelles to provide a clear path for food transport.
100. Which of the following tissues is NOT dead at maturity?
A) Sclerenchyma
B) Cork
C) Phloem fibres
D) Collenchyma
Answer: D
Explanation: Collenchyma cells remain living, unlike sclerenchyma and cork.