Observations from plant breeding and animal husbandry over thousands of years has shown:
variations are limited to the confines of lower taxa
step by step transitions between divisions or phyla have occurred
variation is the result of evolution from one species to another
observable changes from one basic kind into another have never been documented
select all that apply

You have just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. what is the significance of this finding? it will be important to include cysteine in the diet of the mice. cysteine residues are required for the formation of α helices and β pleated sheets. cysteine residues are involved in disulfide bridges that form tertiary structure. cysteine causes bends, or angles, to occur in the tertiary structure of proteins.