Evidence from geology suggests that initially the earth's atmosphere did not contain
a. O2.
b. CO2.
c. H2S.
d. H2O.
e. CH4.
A; O2 was not a major component of the atmosphere until O2-producing photosynthesizers released it in quantity. All the other gases were probably present, although it is hard to determine in what proportions.
You might also like to view...
Select all of the following that are body growth forms of lichens.
_____ crustose _____ fruticose _____ foliose _____ phyticose _____ mycose
A human cell and a mouse cell were experimentally fused, and the results demonstrated that ________
a. proteins cannot move laterally in the membrane b. large polar molecules can enter cells only through transport proteins c. proteins can move laterally in the plasma membrane d. human/mouse chimeric embryos are not viable
You have inherited some old glass baby milk bottles from your grandmother, and you would like to use them instead of plastic bottles. The bottles are placed into a large metal container and placed in the oven at 325°F for about 2 hours. What factor would you change if you wanted the sterilization to occur much quicker?
A. Increase the temperature of the oven by 5 degrees B. Use a pressure cooker to sterilize the bottles with steam C. Place the bottles outside in the sunlight and then place in the oven D. Pour an antimicrobial chemical into the bottles before placing into the oven
The metaphase stage of mitosis is characterized by the
A. arrangement of chromosomes along a line. B. arrangement of chromosomes on a plane. C. division of the centromeres. D. duplication of genetic information.