How come we have 20 amino acids and they make thousands of proteins please give me reasons

Using freezing point depression to find molecular weight lab report

Which of these is the most likely consequence of falling petroleum price

According to piaget, children have acquired the cognitive skill of conservation when they're able to a. understand that six ounces of liquid in a jar and six ounces in an elongated tube are equal. b. understand the viewpoint of other people. c. relate objects around them to their own needs. d. realize that the term heavy describes an object one way and the term big describes it another way. it is not b nor c. did this 2 x wrong..