The disorder caused by an extra X chromosome in males (XXY) is: MCQ with Answer and Explanation

Explanation:
Polygenic inheritance occurs when a single phenotypic trait is controlled by two or more different genes at different loci, each having an additive effect. Human skin color, height, and eye color are controlled by multiple genes (e.g., at least three genes for skin color). This results in a continuous range of phenotypes, forming a bell-shaped curve in a population.

Explanation:
Plastics are synthetic polymers that resist microbial decomposition and persist in the environment for hundreds of years, causing pollution. Paper, cotton, and vegetable waste are biodegradable and broken down by decomposers.

Explanation:
Iron-deficiency anemia is the most prevalent nutritional deficiency worldwide, characterized by fatigue, pallor, and reduced oxygen-carrying capacity. It is treated with iron supplementation and dietary changes.