1. Which of the following is always single-stranded?
   
   

Amessenger RNA (mRNA)

Bdouble-stranded RNA (dsRNA)

CDNA

DDNA and RNA

(obviously its not b.)

1. Which of the following is a difference between DNA and RNA?
   
   

Amost types of RNA are double-stranded

BRNA contains lipids

Cthey have different sugars

DRNA has thymine

1. Which of the following bases are found in RNA but not in DNA?
   
   

Auracil

Bguanine

Cadenine

Dcytosine

I'm pretty sure 3 is a. but I want to be sure.