Q.62 Which of the following matches is/are CORRECT?
(A) Surface fibre – Cotton – Gossypium hirsutum
(B) Bast fibre – Flax – Corchorus capsularis
(C) Drying oil – Safflower oil – Helianthus annuus
(D) Non-drying oil – Castor oil – Ricinus communis

Correct matches are (A) and (D).

Option Analysis

Option A: Surface fibre – Cotton – Gossypium hirsutum
Cotton fibres develop as seed hairs or trichomes on the epidermis of seeds from Gossypium hirsutum, the primary upland cotton species producing over 90% of global cotton lint used in textiles. These are classified as surface fibres due to their location on seed coats, distinct from stem-derived fibres. This match is correct.​

Option B: Bast fibre – Flax – Corchorus capsularis
Bast fibres come from phloem or inner bark of dicot stems, with flax (Linum usitatissimum) as the true source of linen. Corchorus capsularis yields jute, another bast fibre from stems, not flax. This match is incorrect.​

Option C: Drying oil – Safflower oil – Helianthus annuus
Safflower oil from Carthamus tinctorius seeds is a semi-drying or drying oil due to high linoleic acid content, forming films via oxidation. Helianthus annuus produces sunflower oil, a semi-drying oil, not safflower. This match is incorrect.​

Option D: Non-drying oil – Castor oil – Ricinus communis
Castor oil from Ricinus communis seeds remains liquid due to ricinoleic acid’s hydroxyl group, preventing polymerization and film formation. It serves as a non-drying oil in cosmetics and lubricants. This match is correct.​

Surface fibre cotton from Gossypium hirsutum and non-drying oil castor from Ricinus communis represent key correct matches in plant-based natural products, vital for CSIR NET life sciences preparation. These distinctions highlight botanical fibre classifications and oil chemistry, from seed surface fibres to stem bast fibres and oxidation behaviors of seed oils.

Fibre Types Breakdown

• Surface Fibres: Originate from seed coats, like cotton (Gossypium hirsutum) lint fibres, unicellular trichomes 20-30 mm long used in textiles.​

• Bast Fibres: Extracted from stems; flax (Linum usitatissimum) provides linen, while Corchorus capsularis yields jute.​

Drying vs Non-Drying Oils

Drying oils like safflower (Carthamus tinctorius) polymerize via unsaturated fatty acids for paints, unlike non-drying castor oil (Ricinus communis) rich in ricinoleates. Sunflower (Helianthus annuus) falls in semi-drying category.​

This knowledge aids competitive exams by linking plant anatomy to industrial uses.