If 14% of the nucleotides from a DNA molecule contain the base T, what percent will contain the base G?

Question

A.  14%
B.  18%
C.  28%
D.  36%
E.  72%

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain?
 
Gather Content
· What do you already know about base-pairing?
  Consider Possibilities
· What other information is related to the question? Which information is most useful?
 
Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

D.  36%

Clarify Question
  · What is the key concept addressed by the question?
        o This question addresses base-pairing.
· What type of thinking is required?
        o You need to Analyze the information given, using logic, to dissect the problem and determine the answer.
· What key words does the question contain?
        o Nucleotides are the modular units of DNA composed of a phosphate group, a sugar and a nitrogenous base. The four bases, adenine, thymine, guanine and cytosine are abbreviated A, T, G and C, respectively.
 
Gather Content
· What do you already know about base-pairing?
        o Base-pairing is the interaction that connects the two strands of a DNA molecule.
        o A pairs with T, and G pairs with C.
  Consider Possibilities
· What other information is related to the question? Which information is most useful?
        o Since T pairs with A, and G pairs with C, the % of T nucleotides does not equate to the number of G nucleotides.
        o But, it does equate to the number of A nucleotides. For every T in the DNA, there will be an A.
        o So we know there is 14% T and 14% A.
        o We also know there are just four kinds of nucelotides that make up the DNA.
 
Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o Now we can solve this as a math problem.
        o The four types of nucleotides add up to 100%. A + T + C + G = 100%
        o A = T = 14%
        o Since G pairs with C, they also have the save value. G = C
        o 14% + 14% + C + G = 100%
        o 28% + 2G = 100%
        o 2G = 72%
        o 72%/2 = G = 36%
 
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o This question required you to Analyze the information given, using logic, to dissect theproblem and determine the answer.
        o Did you remember that A pairs with T, and G pairs with C?
        o Did you recognize that since they pair, the percent of T is equal to the percent of A?
        o Did you recognize that all four nucleotides must add up to 100%?