The apparatus in the figure was used by Stanley Miller and Harold Urey to study the origin of life on Earth. What compound was excluded from the apparatus so that it would form a reducing atmosphere? 
A. O2
B. H2
C. CO2
D. H2O
E. NH3
Answer: A
You might also like to view...
A team of researchers is studying the external structures on the dorsal (back) surface of a spider mite. The spider mite seems to be the habitat of an even smaller mite, which is approximately 0.05mm. While they can see the dorsal surface of the spider mite with their naked eye, they cannot see the mite clearly. The researchers are writing a grant to provide support for a microscope to use to
study these new mites. They need to purchase a microscope with a high magnification to observe the new mites on their habitat. Based on the information given, what type of microscope would you suggest? A. scanning electron microscope B. no microscope is powerful enough to see the smaller mite C. binocular compound light microscope D. transmission electron microscope
The hormone indicated by the small oval on the left in the figure could be which of the following?
A. testosterone B. insulin C. growth hormone D. ADH
The probability that a boy whose mother is heterozygous for an X-linked trait inherits the recessive allele is
A) 1/16. B) 1/8. C) 1/4. D) 1/2.
Which of the following kingdoms can do photosynthesis?
A. all animals B. some protists C. all bacteria D. some fungi E. all archaea