Is Nitrogen the same as Nitrogen Dioxide (or included in the same category of Nitrogen)? Are they both considered the “most abundant gas in the atmosphere”?

Which symbols below represent the ions found in the glass of water ? a. oh- and h+ b. co2 and o2 c. o2 and h2 d. nh3- and h+

The picture shows a location in india that is very dry and arid. notice the tall mountains in the background; you can find high amounts of vegetation on the other side of the mountains. which statement is most likely true for this area?

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.