Correct Option
The correct option is Chlorophyll a.
Explanation
In plant physiology, paper chromatography is a technique used to separate the various pigments found in leaves. This separation reveals that the green colour of leaves is due to the presence of four distinct pigments rather than a single one. Each pigment exhibits a characteristic colour when separated on a chromatogram.
Analysis of Pigments
- Chlorophyll a: This is the primary photosynthetic pigment. In a chromatogram, it appears as bright or blue-green.
- Chlorophyll b: This is an accessory pigment that absorbs light energy and transfers it to chlorophyll a. It appears as yellow-green.
- Xanthophylls: These are accessory pigments belonging to the carotenoid group. They appear as yellow.
- Carotenoids: These are lipid-soluble pigments that protect chlorophyll from photo-oxidation. They appear as yellow to yellow-orange.
Therefore, the pigment that is characteristically blue-green is Chlorophyll a.
Key Takeaway
Chlorophyll a is the chief pigment associated with photosynthesis and is identified by its blue-green colour in a chromatogram, distinguishing it from the yellow-green Chlorophyll b and yellow/orange carotenoids.