Which valve in the human heart prevents oxygenated blood from going back into the left atrium?
A. bicuspid (mitral) valve
B. aortic semilunar valve
C. pulmonary semilunar valve
D. tricuspid valve
Answer: A
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Catalytic proteins are known as ________ whereas catalytic RNA molecules are known as ________.
A. catalozymes; ribozymes B. enzymes; catalozymes C. ribozymes; enzymes D. enzymes; ribozymes
Which type of plant signaling molecule is similar in structure to aspirin?
a. abscisic acid b. ethylene c. salicylic acid d. jasmonate e. oligosaccharin
The Human Genome Project seeks to
a. identify the nucleotide sequence of all human genes. b. develop a complete DNA library for a human gene. c. develop genetic markers for all genetic diseases. d. catalog all the varieties of human alleles. e. identify all humans that possess genetic defects.
Which of the following is a way that allopolyploidy can most directly cause speciation?
A) It can improve success in island habitats. B) It can overcome hybrid sterility. C) It can change the mating behavior of animals. D) It can generate geographic barriers. E) It can produce heterochrony.