Using the template below that represents the four levels of protein structure, place an X on each level that is expected to be altered as a result of the amino acid substitutions shown in figure 1

The given question is incomplete as there is no figure attached. However, the correct figure is attached to the

Due to the amino acid substitutions, there will be alteration or modification in all the levels of protein structure, since there is an interchange n between two very crucial residues and two amino acids extremely different in nature.

Amino acid substitution is a change in one or more amino acids to another amino acid that takes place in the primary structure. This results in a change in secondary structure and then further. Thus the X should be placed on all the levels of protein structure.

1. glaciers are melting

2. more water going into ocean (water's such as fresh waters, etc)

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .