Scientists believe that the heart of the common (chordate) ancestor of all vertebrates
A. consisted of a single ventricle.
B. had three chambers.
C. had two chambers.
D. had four chambers.
E. was little more than a heavily-muscled region of the ventral artery.
Answer: E
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Fertilization of a human egg takes place in the _____
A) ovary B) oviduct C) cervix D) vagina E) uterus
Electron microscopes differ from light microscopes in that
A. electrons replace light. B. electromagnets replace glass lenses. C. resolution is higher. D. magnification is higher. E. All of the choices are correct.
Imagine a red blood cell leaving the right ventricle of your heart. To which chamber of the heart will that cell return first?
A. right atrium B. left ventricle C. right ventricle D. left atrium E. It is impossible to say from the information given.
If it were found that all animals except the Parazoa had a particular set of genes, one could conclude
A. that those genes probably are related to the embryonic formation of tissues. B. that Darwin was incorrect in his idea about descent with modification. C. that those genes are not useful in interpreting phylogeny. D. that those genes are related to cell wall formation. E. that the Parazoa are not animals.