The first heart sound (lub) is produced by the closing of the __________ and __________ valves
a. aortic semilunar; pulmonary semilunar
b. right atrioventricular; aortic semilunar
c. left atrioventricular; pulmonary semilunar
d. right atrioventricular; left atrioventricular
e. mitral; left atrioventricular
D
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Which of the following contribute(s) to the differences between the Archaea and the bacteria?
A. Archaea differ from bacteria in their tRNA composition, ribosome structure, and antibiotic sensitivity. B. Archaea have isopranyl glycerol ethers rather than fatty acid esters in their membrane lipids. C. Archaea lack muramic acid. D. All of the choices are correct.
Which of the following diseases may manifest themselves with painful genital ulcers?
A. chancroid B. rubeola C. herpes D. leptospirosis E. chancroid AND herpes
Flowers that bloom in early spring versus those that bloom in late summer experience which type of reproductive
isolation?
a. behavioral b. ecological c. gametic d. temporal e. mechanical
Which of the following arose first?
a. animals b. archaea c. fungi d. protists e. plants