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:
spiders are. generally ectotherms.Their internal temperature depends on external temperature transfer.They are also poikilothermic because the body temperature varies with that of the external environment.,
In animals, individual cells are grouped into tissues. e,g Blood. The tissues gives rise to organs.
A main function of most types of epithelial tissue is covering surfaces.They line major all hollow surfaces, and covering body surfaces.
Resorption id the movement of fluid from the glomerular filtrate back into the blood. Ions, glucose,and other escaped metabolites are returned to the blood stream.
In humans, goosebumps are a vestige of a mammalian adaptation to thermoregulation. This is a thermoregulatory mechanism to regulate the body temperature,Goosebumps emits heat, to turn the moisture from the skin to vapour. This evaporate to release this moisture, which cools the body.
Explanation:
The Chondrichthyes are the cartilaginous fishes including the sharks, rays,<span>skates and chimeras. The Osteichthyes are the bony fish. Both of these groups </span>became established during the Devonian Period about 400 million years ago. The Chondrichthyes <span>differ from the Osteichthyes in many respects, including their</span><span>
</span>
Answer:
Explanation:
Proteins are involved in almost every function of cell and inside the body and each protein is specific for its role. Some of them are
1) Protein constitute major part of structure of cell. Proteins are major constituent of cell membrane along with lipids.
2) Enzymes which are proteins in nature catalyze all the important chemical reactions inside and outside the cell e.g transporting material across the cell, synthesizing and repair of DNA
3) Hormones which are proteins play important role in the regulation of metabolic reactions inside the cell
4) Regulation of cell division is performed by DNA-associated proteins
5) Proteins plays important role in storage of iron inside the cells
6) Proteins can be stored as fats inside the body and used as energy when needed by cells for its metabolic activities.
