12 letters · 28 points in Scrabble
noun (genetics) an organism having two different alleles of a particular gene and so giving rise to varying offspring
originFrom hetero- + zygote. Coined by English biologists William Bateson and Edith Rebecca Saunders in 1902, in a paper titled "The facts of heredity in the light of Mendel’s discovery".
Etymology from Wiktionary, CC BY-SA 3.0