Please help! :) As a student who appreciates the importance of the carbon and oxygen cycles, suggest ways to ensure a balance of carbon dioxide and oxygen content in the air.

Which codon is the code for the amino acid histidine (his)?

Which is the graph of the piecewise function f(x)? f(x) = image for option 1 image for option 2 image for option 3 image for option 4

What are the two causes of density in deep current waters? a. salinity (how much salt) of the water and high temperaturesb. salinity (how much salt) of the water and low temperatures c. oxygen content of the water and high temperatures. d. oxygen content of the water and low temperatures