(Q).
Q: What type of organism, including sea stars and sand dollars, is named for their spiny skin? Choices: - mollusks - diatoms - chordates - echinoderms A:
(A).
echinoderms

(Q).
Q: What do the letters in our blood types represent? Choices: - genomes - proteins - iron levels - alleles A:
(A).
alleles

(Q).
Q: Unlike nuclear fission, which involves dangerous radioisotopes, nuclear fusion involves what two harmless elements? Choices: - magnesium and helium - hydrogen and oxygen - hydrogen and carbon - hydrogen and helium A:
(A).
hydrogen and helium