Archaea or archaebacteria
Answer: 20 amino acids
Explanation:
The Genetic code permits the triplet nature of codons whereby three nucleotides from Adenine, Uracil, Guanine and Cytosine on the messenger RNA (mRNA) join to form 64 codons.
Since more than one codon can specify for an amino acid, the 64 codons then specify for 20 amino acids, that then form the sequence of various proteins
Smog is an abiotic factor affecting a biotic factor(s).
This is because smog isn't a living organism so it is abiotic while humans are multicellular organisms so therefore, they are biotic factors.
Smog has a negative effect on many biotic factors.