Aman with free earlobes and the ability to taste ptc marries a woman with free earlobes and no ability to taste ptc. they have four children. all of the children are tasters of ptc. only one has attached earlobes. what are the genotypes of the parents?

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

true                                                                                                       true true true true true true