Personalized Worlds Best Biologist Long Sleeve T-Shirt. Buy a fun World's Best Biologist Long Sleeve T-Shirt - White as a gift for a biology major, biologist, biology teacher too. Great looking sports style logo in navy blue and tan. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL