Transgenic Crops—Golden Rice Phenotype Why does Golden Rice appear pale yellow in color when compared with conventional white rice?

Introduction / Context:Golden Rice is a genetically engineered variety designed to biosynthesize beta-carotene (a provitamin A carotenoid) in the rice endosperm. Vitamin A deficiency is a public health problem in many regions; biofortification aims to address this nutritional gap through staple foods.

Given Data / Assumptions:

• Beta-carotene pigments are yellow to orange.
• The transgenes introduce carotenoid biosynthesis into endosperm tissue that otherwise lacks it.
• Chlorophylls and phycobilins are pigments characteristic of photosynthetic tissues, not rice endosperm.

Concept / Approach:The pale yellow hue results from carotenoid accumulation. Neither chlorophyll a/b nor phycobilins are present in non-photosynthetic seed endosperm under normal conditions. Therefore, beta-carotene is the correct explanation for the color and the nutrition-enhancing property of Golden Rice.

Step-by-Step Solution:

Verification / Alternative check:Analytical profiling of Golden Rice confirms elevated beta-carotene levels; the color intensity correlates with carotenoid content.

Why Other Options Are Wrong:

• Chlorophyll a/b and phycobilins do not accumulate in endosperm.
• Anthocyanins produce red/purple hues, not pale yellow, and are not the engineered trait here.

Common Pitfalls:Assuming all plant pigments are chlorophylls; overlooking tissue specificity of pigment biosynthesis.

Final Answer:It is rich in beta-carotene (provitamin A) accumulated in the endosperm