Asentence with a prepositional phrase inside a gerund phrase

At home, my mom was cooking diner. - Prepositional Phrase
Getting your hair cut to a short, safe length. - Gerund Phrase 

Eating ice cream on a windy day, is the best way for me to go to bed in time.

Okay, biology isn't exactly my strongest subject (it never has been), but i'm pretty sure the answer is nucleotides. dna is made up of nucleotides. each nucleotide contains a phosphate group, a sugar group, and a nitrogen base. there are four different nitrogen bases: adenine (a), thymine (t), guanine (g), and cytosine (c). a always pairs with t, and g always pairs with c.