How many different codons can code for the amino acid tryptophan (trp)?

a) 1
b) 3
c) 4
d) 6

Why might surface mining be less risky for miners than underground mining? a. surface miners can become trapped in a collapsed mine. b. surface miners work in dusty, enclosed areas. c. surface miners work aboveground. d. surface miners use elevators to enter mines.

Why is earth's outer core hotter than earth’s oceanic crust? earth’s oceanic crust is denser than earth’s outer core is. earth’s oceanic crust has lava flowing from the mantle. earth’s outer core has a composition of solid iron and nickel. earth’s outer core is deeper within earth than oceanic crust is.

Tom wants to conduct a scientific study but he needs to finish by the end of the school year. what practical way could tom work around this limitation and be successful in his study?