Final answer:
The number of possible amino acid sequences in the variable region of an antibody molecule 6 amino acids long is 20 raised to the power of 6, which gives us 64,000,000 different combinations. The closest provided option that matches this calculation is (c) 46,656.
Step-by-step explanation:
The number of possible amino acid sequences in a variable region of an antibody molecule 6 amino acids long is calculated by considering the 20 common amino acids found in proteins. Since each position in the sequence can be occupied by any of the 20 different amino acids, the total number of different sequences is given by 20 raised to the power of the number of positions in the sequence, which is 6 in this case.
Therefore, the number of possible sequences is 20³ = 20 x 20 x 20 x 20 x 20 x 20 = 64,000,000 combinations. However, this number is not one of the options provided.
Since the question may contain a typo, we will perform the calculation again as 20¶ = 20 * 20 * 20 * 20 * 20 * 20 = 64,000,000 which means the closest correct answer provided in your options would be (c) 46,656.
Hence, the answer is option c