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"Which of the following would be incapable of exhibiting the type of complementation described in the passage?
A. Recessive mutations
B. Sex-linked recessive mutations
C. Dominant mutations
D. Deletion mutations"
answer:
" C is correct. Answering this question requires a solid understanding of what complementation is all about.
Complementation in diploid organisms occurs when two mutants which affect different genes each provide a
functional protein which the other lacks. A dominant mutation is one which shows a mutant phenotype even when heterozygous, or present in one copy. In other words, there is one wild-type chromosome present in organisms that are heterozygous for a dominant mutation. This wild-type chromosome, although providing a full complement of wild-type proteins, does not complement the dominant mutation; in other words, the mutant phenotype is still expressed. This problem can be approached by eliminating answers that are incorrect. Forexample, choices A and B are both recessive mutations. Recessive mutations don't express their phenotype when they are heterozygous, because the homologous wild-type chromosome provides enough functional protein to make up for that which is defective in the mutant chromosome. In other words, the wild-type chromosome complements the defect present in the mutant chromosome. We can eliminate choices A and B. Choice D can likewise be ruled out; a deletion mutation would most probably be a recessive mutation, because the wild-type chromosome could provide a normal protein product. The correct choice is C."
I didn't include the passage cause it just described an example of how complementation works but i will include it if requested. anyways, i thought the answer could also be C. If males have and X and a Y. then how would complementation work there? the answer didn't make sense to me
A. Recessive mutations
B. Sex-linked recessive mutations
C. Dominant mutations
D. Deletion mutations"
answer:
" C is correct. Answering this question requires a solid understanding of what complementation is all about.
Complementation in diploid organisms occurs when two mutants which affect different genes each provide a
functional protein which the other lacks. A dominant mutation is one which shows a mutant phenotype even when heterozygous, or present in one copy. In other words, there is one wild-type chromosome present in organisms that are heterozygous for a dominant mutation. This wild-type chromosome, although providing a full complement of wild-type proteins, does not complement the dominant mutation; in other words, the mutant phenotype is still expressed. This problem can be approached by eliminating answers that are incorrect. Forexample, choices A and B are both recessive mutations. Recessive mutations don't express their phenotype when they are heterozygous, because the homologous wild-type chromosome provides enough functional protein to make up for that which is defective in the mutant chromosome. In other words, the wild-type chromosome complements the defect present in the mutant chromosome. We can eliminate choices A and B. Choice D can likewise be ruled out; a deletion mutation would most probably be a recessive mutation, because the wild-type chromosome could provide a normal protein product. The correct choice is C."
I didn't include the passage cause it just described an example of how complementation works but i will include it if requested. anyways, i thought the answer could also be C. If males have and X and a Y. then how would complementation work there? the answer didn't make sense to me
