D. Melanogaster

Do you see a relationship between all of these words?

Wingless
Engrailed
Hunchback
Bicoid
Torpedo
Gurken
Pipe
Nudel
Toll
Cactus
Nanos
Spätzel
Sonic Hedgehog
Armadillo
Krüppel
Knirps
Giant
Tailless
Buttonhead
Empty Spiracles
Hairy
Sloppy-paired
Fused
Gooseberry
Pangolin
Huckebein

If you don't, then good for you -- you are a normal person who probably has a life. However, for me, they are all names of genes that affect segmentation patterns in Drosophila, and I have to memorize their functions by tomorrow. Yeah, they are things that determine how fruit flies develop. I know, you are so jealous of me right now.

source

Mhm. That's a fruit fly embryo. Now you know. Have a good weekend.