The ABO blood group antigens do not trigger the formation of memory B cells, so every
immune response is like a first exposure to the antigen. IgM, not IgG antibodies, are
produced in an initial immune response. Explain why a fetus with type B blood is not in
danger if the mother has type A blood. Assume that this is a second pregnancy.

Dna has unique properties that allow it to accurately retain genetic information, even after multiple rounds of replication. one aspect of dna that allows it to accurately store genetic information is the base pairing from chargaff\'s first rule of the four nucleotide bases. if the c content of a dna molecule is 22%, what are the percentages of the remaining bases?

Which of the following describes a difference when gram-positive bacteria are compared to gram-negative bacteria?

Cladistics is a way of classifying organisms by examining the characteristics of their ancestors and descendants and depicting the relationships in a cladogram. which of the following best describes a challenge in classifying organisms this way? a. there are millions of species on earth, and a cladogram is not a practical means for classifying all of them. b. it is impossible to tell which organisms are most closely related to each other using a cladogram. c. cladograms are detail-oriented and do not provide a useful understanding of evolutionary relationships. d. there is a limited number of ways to organize the information, so most cladograms end up looking very similar.