USA Biology Olympiad (USABO) Practice Exam

What is the significance of β-carotene found in "golden rice"?

1. It is used for energy storage

2. It is an essential fatty acid

3. It acts as a precursor for vitamin A

4. It is a primary source of protein

The correct answer is: It acts as a precursor for vitamin A

The significance of β-carotene in golden rice is that it acts as a precursor for vitamin A. Golden rice has been genetically modified to produce higher levels of β-carotene, which is a type of carotenoid that the body can convert into vitamin A. Vitamin A is crucial for several biological functions, including vision, immune system performance, and skin health. This modification aims to address vitamin A deficiency, which is prevalent in some parts of the world and can lead to severe health issues, including blindness and increased mortality rates. In terms of nutritional roles, β-carotene is not used for energy storage, nor is it classified as an essential fatty acid, which are necessary components of lipids in the body. It also doesn’t serve as a primary source of protein, as proteins are made up of amino acids, whereas β-carotene is a carotenoid pigment. Thus, its most important aspect in the context of golden rice and nutritional science is its role as a precursor for vitamin A, making option C the most significant and relevant choice.