Hmmm i think its the third one because men only have 1 x chromosome therefore without the other one if the x chromosome on a men carries a disorder it will show because there is no other chromosome to balance it out and in women the disorder has to show on both X chronosome (and its rarer) for a disorder to appear therefore women having a second X chromosome is effectively a protection
The two important features that characterize the adaptive immune system are specificity and memory.
The ability of the adaptive immune system to target specific pathogen and generate a tailored immune response against it is termed as specificity.
The ability of the adaptive immune system to remember the first exposure to the pathogen and thus, generate a heightened and more rapid immune response against the same pathogen on subsequent exposure is termed as memory.