General anatomy of root (monocot & dicot) MCQs With Answer

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Introduction: Understanding the general anatomy of root (monocot & dicot) is essential for B.Pharm students studying plant-based drugs, extraction sources, and pharmacognosy. This concise guide covers root histology, root cap, apical meristem, cortex, endodermis with Casparian strip, pericycle, vascular cylinder, xylem-phloem arrangement, and differences between monocot root and dicot root including secondary growth and presence of pith. Emphasis on functional anatomy—root hairs, lateral root origin, and modifications for storage or aeration—helps link structure to pharmacological relevance. Clear, exam-oriented MCQs reinforce concepts and clinical plant identification skills. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which zone of the root is primarily responsible for cell elongation and increase in root length?

  • Zone of cell division
  • Zone of elongation
  • Zone of maturation
  • Root cap

Correct Answer: Zone of elongation

Q2. The root cap primarily functions to:

  • Synthesize chlorophyll for photosynthesis
  • Protect the apical meristem and assist in soil penetration
  • Conduct water and minerals to the stem
  • Produce lateral roots

Correct Answer: Protect the apical meristem and assist in soil penetration

Q3. Which tissue gives rise to vascular tissues (xylem and phloem) during primary root development?

  • Protoderm
  • Ground meristem
  • Procambium
  • Pericycle

Correct Answer: Procambium

Q4. In roots, the Casparian strip is located in which cell layer?

  • Epidermis
  • Cortex
  • Endodermis
  • Pericycle

Correct Answer: Endodermis

Q5. The Casparian strip is primarily composed of:

  • Cellulose
  • Suberin
  • Lignin only
  • Pectin

Correct Answer: Suberin

Q6. Root hairs are single-celled extensions of which tissue?

  • Endodermis
  • Pericycle
  • Epidermis
  • Cortex

Correct Answer: Epidermis

Q7. Lateral roots originate endogenously from which layer?

  • Pericycle
  • Endodermis
  • Cortex
  • Epidermis

Correct Answer: Pericycle

Q8. In a typical dicot primary root cross-section, xylem is arranged as:

  • A central solid core with phloem between xylem arms (radial pattern)
  • Scattered vascular bundles
  • A ring with central pith
  • Discrete collateral bundles as in stem

Correct Answer: A central solid core with phloem between xylem arms (radial pattern)

Q9. Monocot roots commonly differ from dicot roots by having:

  • A central x-shaped xylem with no pith
  • Polyarch xylem arrangement and often a central pith
  • Secondary growth via vascular cambium
  • Only two xylem arms (diarch)

Correct Answer: Polyarch xylem arrangement and often a central pith

Q10. Secondary growth in roots (formation of wood and bark) is typically observed in:

  • Most monocots
  • Bryophytes
  • Dicots and gymnosperms with active vascular cambium
  • Algae

Correct Answer: Dicots and gymnosperms with active vascular cambium

Q11. The pericycle’s role includes all EXCEPT:

  • Initiation of lateral roots
  • Contributing to vascular cambium in secondary growth
  • Forming root hairs
  • Participating in wound repair

Correct Answer: Forming root hairs

Q12. In roots, protoxylem maturation is typically described as:

  • Endarch (protoxylem toward center)
  • Exarch (protoxylem toward periphery)
  • Centrarch (protoxylem in the center)
  • Tangential

Correct Answer: Exarch (protoxylem toward periphery)

Q13. The cortical region of the root is mainly composed of:

  • Sclerenchyma cells rich in lignin
  • Parenchyma cells for storage and transport
  • Collenchyma for mechanical support
  • Vascular bundles for conduction

Correct Answer: Parenchyma cells for storage and transport

Q14. Passage cells in the endodermis are characterized by:

  • Heavy suberization of all walls
  • Thin walls and lack of Casparian strip
  • Retained primary walls without heavy suberization adjacent to xylem
  • Thick lignified walls for support

Correct Answer: Retained primary walls without heavy suberization adjacent to xylem

Q15. The stele type commonly observed in most flowering plant roots is called:

  • Atactostele
  • Protostele (solid vascular core)
  • Siphonostele
  • Collenchymastele

Correct Answer: Protostele (solid vascular core)

Q16. Which statement about root epidermis is correct?

  • It has multiple layers in most angiosperms
  • It is frequently suberized to prevent water loss
  • It usually lacks stomata and is single-layered
  • It contains vascular bundles

Correct Answer: It usually lacks stomata and is single-layered

Q17. Root nodules in legumes are primarily associated with which cell or tissue type for development?

  • Epidermis
  • Pericycle and cortical cells (endogenous origin)
  • Xylem vessels
  • Endodermis only

Correct Answer: Pericycle and cortical cells (endogenous origin)

Q18. Which characteristic is typical of a monocot root cross-section?

  • Xylem forming a cross with phloem between arms
  • Central pith surrounded by a ring of vascular tissue
  • Well-defined secondary xylem and phloem secondary growth
  • Collateral vascular bundles scattered in ground tissue

Correct Answer: Central pith surrounded by a ring of vascular tissue

Q19. The meristematic region of the root apex includes which of the following initials?

  • Protoderm, ground meristem, procambium
  • Sclerenchyma, collenchyma, parenchyma
  • Epidermis, periderm, endodermis
  • Phloem, xylem, cambium

Correct Answer: Protoderm, ground meristem, procambium

Q20. In roots, the vascular bundle arrangement is termed ‘radial’ meaning:

  • Xylem and phloem lie side by side in the same radius
  • Xylem and phloem are arranged alternately along radii
  • Vascular bundles are scattered randomly
  • There is a continuous ring of phloem outside xylem

Correct Answer: Xylem and phloem are arranged alternately along radii

Q21. Which hormone primarily promotes lateral root initiation from the pericycle?

  • Cytokinin
  • Auxin (Indole-3-acetic acid)
  • Gibberellin
  • Abscisic acid

Correct Answer: Auxin (Indole-3-acetic acid)

Q22. Root hairs increase absorptive surface area and are most abundant in which zone?

  • Root cap zone
  • Zone of elongation
  • Zone of maturation (root hair zone)
  • Zone of cell division

Correct Answer: Zone of maturation (root hair zone)

Q23. Which structural feature prevents apoplastic movement of solutes into the stele?

  • Root hairs
  • Casparian strip in endodermis
  • Pericycle lignification
  • Cortex plasmodesmata

Correct Answer: Casparian strip in endodermis

Q24. In dicot roots undergoing secondary growth, the vascular cambium forms between:

  • Epidermis and cortex
  • Primary xylem and primary phloem
  • Primary xylem and primary phloem (interfascicular and fascicular cambium combine)
  • Endodermis and pericycle

Correct Answer: Primary xylem and primary phloem (interfascicular and fascicular cambium combine)

Q25. Pneumatophores are modified roots primarily for:

  • Water storage in deserts
  • Aerial support in tall trees
  • Gas exchange in waterlogged soils
  • Seed dispersal

Correct Answer: Gas exchange in waterlogged soils

Q26. A storage root specialized for carbohydrate accumulation is called:

  • Pneumatophore
  • Prop root
  • Tuberous root
  • Adventitious root

Correct Answer: Tuberous root

Q27. The term ‘polyarch’ refers to roots having:

  • Only two xylem arms
  • Multiple xylem arms (>6) arranged around the center
  • A single central xylem strand
  • No xylem present

Correct Answer: Multiple xylem arms (>6) arranged around the center

Q28. Adventitious roots typically arise from:

  • Pericycle of primary roots only
  • Stem, leaf or other non-root tissues
  • Endodermis exclusively
  • Only from root tips

Correct Answer: Stem, leaf or other non-root tissues

Q29. The periderm replaces which tissue during secondary growth?

  • Epidermis
  • Endodermis
  • Cortex
  • Vascular cambium

Correct Answer: Epidermis

Q30. Which of the following is TRUE about root xylem and phloem in a typical root?

  • They are organized in collateral bundles as in stems
  • Xylem and phloem are arranged alternately in radial pattern
  • Phloem forms a central core surrounded by xylem
  • They are absent in primary roots

Correct Answer: Xylem and phloem are arranged alternately in radial pattern

Q31. In roots, the innermost cortex cell layer that regulates flow into the vascular cylinder is the:

  • Epidermis
  • Endodermis
  • Pericycle
  • Exodermis

Correct Answer: Endodermis

Q32. Which structure secretes mucilage and helps lubricate root passage through soil?

  • Root hairs
  • Quiescent center
  • Root cap (columella and peripheral cells)
  • Pericycle

Correct Answer: Root cap (columella and peripheral cells)

Q33. The quiescent center in the root apical meristem is important because it:

  • Produces root hairs directly
  • Serves as a zone of relatively inactive cells that can replace damaged meristematic cells
  • Is the site of secondary growth initiation
  • Forms the Casparian strip

Correct Answer: Serves as a zone of relatively inactive cells that can replace damaged meristematic cells

Q34. Which cell wall deposition is typical in cells of the Casparian strip?

  • Cellulose-only deposition
  • Suberin and lignin deposition in radial and transverse walls
  • Pectin-rich wall without hydrophobic materials
  • Chitin deposition

Correct Answer: Suberin and lignin deposition in radial and transverse walls

Q35. The origin of root vascular cambium during secondary thickening is primarily from:

  • Pericycle and residual procambial cells
  • Endodermis only
  • Epidermis and cortex fusion
  • Root hairs

Correct Answer: Pericycle and residual procambial cells

Q36. Which root type is typical of many monocots and helps in anchorage rather than deep penetration?

  • Tap root system
  • Fibrous root system
  • Pneumatophore system
  • Tuberous taproot

Correct Answer: Fibrous root system

Q37. A distinguishing microscopic feature of many monocot roots is:

  • Formation of a cork cambium early for secondary growth
  • Presence of pith at center surrounded by vascular ring
  • Cross-shaped xylem with no phloem
  • Highly suberized epidermis with stomata

Correct Answer: Presence of pith at center surrounded by vascular ring

Q38. In roots, plasmodesmata primarily facilitate which route of transport?

  • Apoplastic route
  • Symplastic route
  • Transmembrane diffusion only
  • Vesicular transport exclusively

Correct Answer: Symplastic route

Q39. The term ‘endogenous’ in reference to lateral root formation means:

  • Lateral roots form from the outer tissues and grow outward
  • Lateral roots originate from internal tissues and grow outward through outer layers
  • Lateral roots are produced only by aerial shoots
  • Lateral roots are initiated by fungal infection

Correct Answer: Lateral roots originate from internal tissues and grow outward through outer layers

Q40. Which feature is commonly absent in monocot roots compared to dicot roots?

  • Root hairs
  • Secondary growth via vascular cambium
  • Primary xylem and phloem
  • Endodermis with Casparian strip

Correct Answer: Secondary growth via vascular cambium

Q41. In root cross-sections, phloem rays are generally:

  • Prominent and numerous as in stems
  • Absent; roots have radial vascular arrangement with separate phloem patches
  • Continuous sheets of phloem around xylem
  • Composed only of lignified fibers

Correct Answer: Absent; roots have radial vascular arrangement with separate phloem patches

Q42. Which statement best describes the function of the endodermis in medicinal plant roots relevant to drug extraction?

  • It stores alkaloids in large vacuoles for easy extraction
  • It regulates radial solute movement into the vascular system, influencing compound translocation
  • It secretes enzymes that degrade active constituents
  • It produces cork cells containing volatile oils

Correct Answer: It regulates radial solute movement into the vascular system, influencing compound translocation

Q43. Which structure in the root is most directly involved in water uptake from soil?

  • Xylem vessels in the stele
  • Root hairs on epidermal cells
  • Pericycle meristem
  • Endodermal Casparian strip

Correct Answer: Root hairs on epidermal cells

Q44. The anatomical adaptation of storage roots (e.g., sweet potato) often includes:

  • Extensive development of sclerenchyma for rigidity
  • Large parenchymatous cortex and stele rich in starch-filled cells
  • Increased stomatal density on the surface
  • Elimination of the endodermis

Correct Answer: Large parenchymatous cortex and stele rich in starch-filled cells

Q45. ‘Exodermis’ in some roots refers to:

  • An inner layer of the stele replacing xylem
  • A suberized outer cortical layer functioning like a secondary epidermis
  • The primary epidermis with root hairs
  • The meristematic zone at the apex

Correct Answer: A suberized outer cortical layer functioning like a secondary epidermis

Q46. The primary function of the pericycle in lateral root emergence is to:

  • Provide the epidermal covering for new roots
  • Divide and form the new root primordium internally
  • Form the root cap for the lateral root
  • Produce root hairs directly

Correct Answer: Divide and form the new root primordium internally

Q47. In pharmacognosy, why is knowledge of root anatomy important for B.Pharm students?

  • It helps identify plant drugs, locate storage tissues of active compounds, and understand translocation pathways
  • It is not relevant since drugs are only synthesized chemically
  • Because roots are the only plant source for medicines
  • It focuses exclusively on leaf stomatal patterns

Correct Answer: It helps identify plant drugs, locate storage tissues of active compounds, and understand translocation pathways

Q48. In roots showing secondary growth, cork cambium (phellogen) arises from:

  • Endodermis or outer cortex cells
  • Procambium only
  • Vascular cambium exclusively
  • Root cap cells

Correct Answer: Endodermis or outer cortex cells

Q49. The presence of a multi-layered cortex and abundant aerenchyma is an adaptation commonly seen in:

  • Desert plants for water conservation
  • Aquatic and marsh plants for buoyancy and gas exchange
  • Epiphytic orchids for nutrient uptake
  • Conifer roots for resin storage

Correct Answer: Aquatic and marsh plants for buoyancy and gas exchange

Q50. Which feature aids in distinguishing a dicot root cross-section from a monocot root cross-section under microscope?

  • Dicot roots commonly have a central pith surrounded by scattered vascular bundles
  • Monocot roots often lack endodermis while dicots have it
  • Dicot roots usually show a central xylem core with phloem between arms and absence of large central pith
  • Monocot roots always undergo secondary growth

Correct Answer: Dicot roots usually show a central xylem core with phloem between arms and absence of large central pith

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