Morphology and histology of Senna MCQs With Answer

Morphology and histology of Senna MCQs With Answer

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Morphology and histology of Senna MCQs With Answer

Senna, a medicinal genus in the Fabaceae family, is important in pharmacognosy for its characteristic morphology and distinctive histological features used in drug identification. B.Pharm students should master leaf architecture (pinnately compound leaflets, hypostomatic epidermis), floral and fruit structure (five petals, leguminous pods), and microscopic traits such as palisade and spongy mesophyll, collateral vascular bundles, calcium oxalate crystals, fibres and vessels. Knowledge of powder microscopy and diagnostic chemical tests for anthraquinone glycosides (sennosides) is essential for quality control. This concise, keyword-rich overview prepares you for practical identification and exam questions. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which family does Senna belong to?

  • Fabaceae
  • Asteraceae
  • Lamiaceae
  • Rosaceae

Correct Answer: Fabaceae

Q2. What is the typical leaf type of Senna?

  • Pinnately compound
  • Palmately compound
  • Simple
  • Bipinnate

Correct Answer: Pinnately compound

Q3. How are Senna leaves arranged on the stem?

  • Alternate
  • Opposite
  • Whorled
  • Basal rosette

Correct Answer: Alternate

Q4. Senna leaflets are typically:

  • Hypostomatic (stomata only on lower surface)
  • Amphistomatic (stomata on both surfaces)
  • Epistomatic (stomata only on upper surface)
  • Astomatic (no stomata)

Correct Answer: Hypostomatic (stomata only on lower surface)

Q5. What is the common stomatal type observed in Senna epidermis?

  • Paracytic
  • Anomocytic
  • Diacytic
  • Tetracytic

Correct Answer: Paracytic

Q6. The mesophyll of Senna leaflet is described as:

  • Dorsiventral with palisade and spongy parenchyma
  • Isobilateral with equal palisade on both sides
  • Homogenous chlorenchyma throughout
  • Composed only of collenchyma

Correct Answer: Dorsiventral with palisade and spongy parenchyma

Q7. The vascular bundle type in Senna midrib is:

  • Collateral (xylem adaxial, phloem abaxial)
  • Bicollateral (phloem on both sides of xylem)
  • Concentric (xylem surrounds phloem)
  • Amphivasal (phloem surrounds xylem)

Correct Answer: Collateral (xylem adaxial, phloem abaxial)

Q8. Which type of crystals are commonly found in Senna tissues?

  • Calcium oxalate crystals
  • Silica bodies
  • Calcium carbonate concretions
  • No crystals present

Correct Answer: Calcium oxalate crystals

Q9. What is the fruit type of Senna?

  • Legume (pod)
  • Capsule
  • Berry
  • Drupe

Correct Answer: Legume (pod)

Q10. How many petals are typically present in a Senna flower?

  • 3
  • 4
  • 5
  • 6

Correct Answer: 5

Q11. The usual number of stamens in Senna flowers is:

  • 5
  • 8
  • 10
  • Numerous (>20)

Correct Answer: 10

Q12. What is the ovary position in Senna flowers?

  • Superior
  • Inferior
  • Half-inferior
  • Epigynous

Correct Answer: Superior

Q13. The primary pollination syndrome of Senna is:

  • Anemophily (wind)
  • Entomophily (insect)
  • Hydrophily (water)
  • Autogamy (self-pollination)

Correct Answer: Entomophily (insect)

Q14. In powder microscopy of Senna leaf, which components are commonly observed?

  • Epidermal fragments and stomatal remnants
  • Fibres, vessels and stone cells
  • Calcium oxalate crystals
  • All of the above

Correct Answer: All of the above

Q15. The epidermis of Senna leaf is characteristically covered by:

  • A cuticle of variable thickness (often distinct)
  • No cuticle
  • Suberin layer only
  • A thick cork layer

Correct Answer: A cuticle of variable thickness (often distinct)

Q16. When present, the trichomes on Senna leaves are usually:

  • Simple, unbranched hairs
  • Glandular multicellular hairs
  • Stellate (branched) hairs
  • Scale-like peltate hairs

Correct Answer: Simple, unbranched hairs

Q17. Venation pattern in Senna leaflets is best described as:

  • Pinnate reticulate venation
  • Parallel venation
  • Dichotomous venation
  • Palmate venation

Correct Answer: Pinnate reticulate venation

Q18. Vascular bundles in the Senna lamina are often capped by:

  • Sclerenchymatous bundle sheath (bundle cap)
  • A layer of collenchyma only
  • Cuticular thickenings
  • Secretory ducts

Correct Answer: Sclerenchymatous bundle sheath (bundle cap)

Q19. The palisade layer in Senna leaf typically consists of:

  • One or two layers of elongated palisade cells
  • More than five layers of palisade cells
  • No palisade cells (only spongy parenchyma)
  • A single layer of collenchyma

Correct Answer: One or two layers of elongated palisade cells

Q20. Does the stem of Senna show secondary growth in mature plants?

  • Yes, secondary growth is commonly observed in mature stems
  • No, stems remain purely primary
  • Only in seedlings
  • Only in roots

Correct Answer: Yes, secondary growth is commonly observed in mature stems

Q21. Seeds of Senna typically have which characteristic?

  • Hard testa (seed coat)
  • Winged and papery
  • Fleshy arillate coat
  • Hairy surface

Correct Answer: Hard testa (seed coat)

Q22. Which microscopic fragments are diagnostic in Senna leaf powder?

  • Trichome bases and stomatal fragments
  • Only chloroplast-rich mesophyll fragments
  • Only seed coat fragments
  • Only epidermal scales

Correct Answer: Trichome bases and stomatal fragments

Q23. A pulvinus is associated with Senna leaves. Where is it located?

  • At the base of the petiole and often at leaflet bases
  • Only at the stem node
  • Only on the flower pedicel
  • Absent in Senna

Correct Answer: At the base of the petiole and often at leaflet bases

Q24. Which tissue commonly stores carbohydrates (starch) in Senna leaf?

  • Parenchyma (chlorenchyma)
  • Collenchyma
  • Sclerenchyma
  • Epidermis

Correct Answer: Parenchyma (chlorenchyma)

Q25. Which class of secondary metabolites is chiefly responsible for Senna’s laxative activity?

  • Anthraquinone glycosides (sennosides)
  • Alkaloids
  • Essential oils
  • Tannins

Correct Answer: Anthraquinone glycosides (sennosides)

Q26. Which reagent is commonly used to detect lignified elements in plant sections?

  • Phloroglucinol-HCl
  • Iodine-potassium iodide (I2/KI)
  • Methylene blue
  • Molisch reagent

Correct Answer: Phloroglucinol-HCl

Q27. Which chemical test is classically used to indicate presence of anthraquinones in Senna?

  • Bornträger’s test (after alkaline extraction)
  • Benedict’s test
  • Biuret test
  • Fehling’s test

Correct Answer: Bornträger’s test (after alkaline extraction)

Q28. In a transverse section of Senna leaflet, the xylem is oriented towards which surface?

  • Adaxial (upper) surface
  • Abaxial (lower) surface
  • Equally distributed on both surfaces
  • Only at the margin

Correct Answer: Adaxial (upper) surface

Q29. Powder fragments showing stomatal complexes in Senna are most likely from which stomatal type?

  • Paracytic stomatal complexes
  • Anomocytic stomatal complexes
  • Diacytic stomatal complexes
  • Tetracytic stomatal complexes

Correct Answer: Paracytic stomatal complexes

Q30. Which characteristic chemical marker is most useful for distinguishing Senna crude drug during quality control?

  • Presence of sennosides (anthraquinone glycosides)
  • High essential oil content
  • Alkaloid fingerprint
  • Presence of mucilage

Correct Answer: Presence of sennosides (anthraquinone glycosides)

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