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.
Answer:
B
Explanation:
all of the options are correct and are examples of those energy forms
Double fertilization results in the formation of one diploid embryo and a triploid endosperm. Double fertilization is characterized by the formation of two embryos; the embryo proper which is diploid and the fusion product of the central cell with one male gamete which is triploid. This secondary triploid zygote develops into the endosperm.
We should expect that the rat will have have more difficulty in learning the task compared to a normal rat. This is because the rat has been injected with a certain drug that oppresses the dopamine activity. And then the rat is placed in an operant chamber where a lever-pressing task is shaped through positive reinforcement.
