Answer:
Three nucleotide
Explanation:
Three nucleotides are required to code for one amino acid. There are four types of nucleotides A, T, G, C which make DNA. So a doublet of nucleotide code which involves only two nucleotide would be insufficient to code for 20 amino acids because if 4 different nucleotide is taken two at a time then it can only produce 16 amino acid(4²=16).
But if we take three-nucleotide than the number reaches 64 which is more than sufficient to code for 20 different amino acids(4³= 64). Therefore 3 nucleotides are needed to code for an amino acid.
Dichotomous Key with smiles
1. Teeth visible ....................go to 2
.....Teeth not visible .................go to 4
2. Has a wide, toothy smile .......Smilus toothyus
....Is not smiling ......................go to 3
3. Visibly crying .................Smilus dramaticus
.... Frowning .......................Smilus upsettus
4. Eyes are symmetrical .... go to 5
....Eyes not symmetrical .....go to 8
5. Eyes shaped like hearts ..... Smilus valentinus
....Eyes are shaped as ovals .....go to 6
<span>
</span>6. Smiling, happy face ...... Smilus traditionalis
.....Not happy, frowning or other .....go to 7
7. Mouth curved down, frowning .... Smilus saddus
.... Mouth is a small circle .................Smilus suprisus
8. Has a pirate eye patch ...............Smilus piratus
....Does not have eye patch ............ go to 9
9. One eye is much larger than the other eye ..... Smilus mutatus
One eye is winking .................Smilus winkus
Seeing that our species is constantly evolving, maybe it is starting to get more uncomfortable to walk on all fours.
A&E Maybe hope this helps you out for this subject
