#1 A-Z: ALLELES AND CHROMOSOMES
People tend to notice that brothers and sisters (or even cousins) look alike. Because you are a smart human being, you know that your physical appearance is controlled by a masterful molecule called DNA. And you know that as siblings share the same parents, they share DNA, and hence look similar. DNA resides within the nucleus of every cell, forming a complex network called chromatin when paired with with storage proteins called histones. During cell division, this chromatin condenses into the familiar structures we call chromosomes ¹. What lies within these chromosomes, and how do they influence our traits? The answer lies in genes- the fundamental units of inheritance. Genes are sections of DNA located at specific positions on the chromosome ², called loci. Genes are passed on from parents to offspring and contain the necessary information to make you, you. An excellent diagr...