Final answer:
Using Chargaff's Rule, 16% of the alien genome is comprised of G, and 22% is comprised of T. Percentages for A and X cannot be determined without additional information.
Step-by-step explanation:
Given that 16% of the alien genome is comprised of nucleotides containing C, and 22% is comprised of nucleotides containing Y, we can calculate the percentages of the remaining nucleotides by applying Chargaff's Rule, which states that DNA is a double helix that is held together by base pairs: A pairs with T, and G pairs with C. This means that the percentage of nucleotides containing G will be equal to that of C, and T will complement Y assuming that Y pairs with T in this alien genome, as A pairs with T in Earth organisms.
(a) Since 16% of the alien genome is comprised of C, then 16% of the alien genome is also comprised of G, as G pairs with C.
(b) If 22% is comprised of Y, and assuming Y pairs with T, then 22% of the alien genome is comprised of T.
(c) To find the percentage of A, we would need additional information since the question doesn't provide a direct pairing percentage. Given no other information, the percentage of A remains undetermined in this hypothetical situation.
(d) Without additional information about what X pairs with, we cannot accurately determine the percentage of X in the alien genome. If X pairs with an unknown or non-standard base or does not directly pair with one of the given nucleotides, we would not be able to apply Chargaff's Rule.