Well, it’s just because nucleotides do not contain an amino group. Nucleotides are composed of nitrogen base bonded to a sugar which is also bonded to a phosphate group. No amino groups in sight.
These are small eukaryotes
Answer: It filters waste out of your body. Think of "excretory" as "expelling" something gross.
A scientific explanation is backed up with data, experiments, observations, and has a large amount of evidence. A non-scientific explanation is usually backed up with beliefs, and opinions. There is no "science" behind that type of explanation.
