Which chordate feature is the only one remaining in adult tunicates?
a. notochord
b. dorsal tubular nerve cord
c. gill slits
d. postanal tail

answer; i do believe that the correct answer is; ///mendelian genes are at specific loci on the chromosome and, in turn, segregate during meiosis;

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.