Q.Golden rice is:

Golden rice is a landmark example of genetic engineering applied to address nutritional deficiency. It was developed by inserting genes responsible for β-carotene biosynthesis into rice plants. β-carotene is the precursor of vitamin A, and its presence gives the rice grains a characteristic golden-yellow colour — hence the name.

The primary goal was to combat vitamin A deficiency, which is a major public health problem in developing countries where rice is a staple food. Normal rice varieties lack β-carotene in the endosperm (the edible part), so this transgenic approach aimed to biofortify the crop. The genes introduced enable the rice plant to produce and accumulate β-carotene in the grain itself. …

The story of golden rice sits at the intersection of biotechnology and public health. To understand what makes it "golden," we need to first grasp what genetically modified organisms are and why scientists would want to alter rice in the first place.

Rice is a staple food for billions, particularly in Asia and Africa, but polished white rice lacks vitamin A. Vitamin A deficiency is a serious public health problem in developing countries, causing blindness in children and weakening immune systems. The human body can convert β-carotene (the pigment that makes carrots orange) into vitamin A, but ordinary rice plants don't produce β-carotene in their endosperm—the starchy part we eat.

This is where genetic engineering enters. Scientists inserted genes from other organisms into rice plants to enable them to synthesize β-carotene in the grain itself. The presence of β-carotene gives the rice grains a golden-yellow colour, hence the name "golden rice." This is a transgenic crop—one that carries genes transferred from other species.

Let's examine why the other options don't fit:

• The Yellow River in China is indeed a major rice-growing region, but golden rice isn't defined by geography. It's a laboratory-created variety that can theoretically be grown anywhere suitable for rice cultivation.
• Old rice does sometimes develop a yellowish tint due to aging and oxidation, but this has nothing to do with nutritional enhancement or genetic modification. …

Method — separate the true fact from the 3 distractors

• (a) references a real river (Yellow River) but has nothing to do with genetic engineering — a geography trap.
• (b) "stored rice with a tint" — describes ordinary rice ageing, not genetic modification. …