The stronger survived and the weaker passed on... Those with a weaker immune system had trouble with sickness and usually ended up passing on but those with strong immune systems were stronger and healthier and lived.
Answer:
B) Nitrogen-fixing bacteria and lightning
Explanation:
Nitrogen cycle is the natural process in which atmospheric nitrogen is converted into nitrite and nitrate with the help of bacteria.
Nitrogen cycle is directly dependent on nitrogen-fixing bacteria and lightning.
As bacteria are responsible for most of the chemical conversion in the nitrogen cycle such as nitrogen fixation (first step) is done by soil bacteria (Cyanobacteria) that form ammonia, which is toxic to plants; nitrification in which ammonia is converted into nitrites and nitrates with the help of Nitrobacter and denitrification bacteria involve Pseudomonas, and Achromobacter which convert nitrite and nitrate into nitrogen.
The lightning breaks nitrogen molecules and allow it to combine with oxygen in atmosphere which further dissolve in rain and form nitrates.
Hence, the nitrogen cycle is most directly dependent upon nitrogen-fixing bacteria and lightning and the correct option is B.
False
Nitrogen and sulfur dioxide are acidic oxides in nature. The burning of fossil fuels and other sources are responsible for addition of these oxides in the atmosphere of earth. These oxides mixed with water vapor causes acid rain. Being acidic in nature they will have low pH value. Therefore, greater the concentration of sulfur and nitrogen oxides, will lower the pH value of precipitation.
hope this helps:)sorry if it doesnt
