The molecules present in animal tissues can be arranged into three groups. 1 glucose, cholesterol, triglycerides, water 2 glycogen, antibodies, adenine, phospholipids 3 haemoglobin, carbon dioxide, mRNA, monosaccharides Which of these groups contain one or more molecules that always have nitrogen atoms?
- A1, 2 and 3
- B1 and 2 only
- C1 and 3 only
- D2 and 3 only