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.
Fruit growing have following economic and
nutritional advantages. High productivity: High
yield per unit area: From a unit area of land more
yield is realized from fruit crops than any of the
agronomic crops. The average yields of Papaya,
Banana and Grapes are 10 to 15 times more that of agronomic crops.
1Answer:
The correct answer is - D. how changes in biodiversity impact an ecosystem.
Explanation:
The water hyacinth is an invasive plant species that rapidly grows and creates a thick layer over the water surface in almost every aquatic ecosystem. The growth of the layer of this species causes problems to the environment, ecosystem, humans, and other species.
These aquatic plants reduce the oxygen level and other nutrients from the ecosystem it is introduced and affect the biodiversity by increasing heavy metals and contaminants.
The layer of this plant inhibits photosynthesis that decreases sugar and energy production and blocks the boat and ship movements and economically as well.
