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.
<span>The answer is c. Chromosomes carry the codes for hereditary traits. Chromosomes are thread-like structures made of proteins and DNA. Codes for hereditary traits are present in a molecule of DNA. Chromosomes can be found in the nucleus of each cell. Humans have 46 chromosomes in each cell (not 460) arranged in 23 pairs (not 230). Hope this helps. Let me know if you need additional help!</span>
The correct answer is 'If molecules are small enough, then they can pass through the semipermeable membrane because they can cross the semipermeable membrane from their small pores or openings'.
The semipermeable membrane is permeable to few molecules, and the smaller molecules pass through the molecules from small pores present in the semipermeable membrane. The size of the big molecules are large, so, they cannot cross through semipermeable membrane.
<span>Killer whales are much more common in highly productive cold water areas. These include the Atlantic, the Pacific Northwest, and the higher latitudes of the Southern Ocean.</span>
