I am not a biology expert but I have done some homework on understanding alleles, chromosomes, dna in the human genome. Still baffled by a question though:
As I understand it at a particular locus for e.g. if a human has a A on one chromosome and a G on another that individual is considered Heterozygous at that locus because of the difference in the nucleotides (A/G in this case).
However, my question is. What about an individual that has an A on the 3' -> 5' strand (and hence a complement T on the 5'-> 3' strand) on one chromosome but T on the 3'-> 5' (and its complement on the other strand) on the other chromosome. Is this individual considered heterozygos or homozygous?
Basically my question boils down to does the "directionality" of the A-T pairing matter on both chromosomes?
I was thinking it should as only one strand can code for genes which the other doesn't so it should matter whether the A is on the (3'-5') or on the other strand..
Any advice would be great!