Answer:
Nitrogen cycle works through various stages like, nitrogen fixation, nitrification, assimilation, ammonification, denitrification etc. It is a building block for protein and DNA
Explanation:
Nitrogen is an element abundantly found in the atmosphere, also its building block for proteins as well as nucleic acid i.e. DNA formation. In nitrogen cycle , the nitrogen is being prepared from inert nitrogen. The nitrogen cycle has several processes like nitrogen fixation, in this the inert nitrogen is being converted to organic nitrogen with the help of certain micro-organism.
Nitrification, plants cannot absorb directly nitrogen so bacteria help the plants to convert the nitrogen into ammonia form in this stage. Assimilation, another stage in which plants starts absorbing various forms of nitrogen from the soil.i.e. nitrate, nitrite and ammonium. Ammonification, here plants and animals have nitrogen in there body after death various microbes help in decomposition in this stage. Denitrification, in this stage the return back of nitrogen takes place.
DNA is the main type of genetic material found in a cell. In addition, it is found in the nucleus of the cell, so (D) is correct. DNA in the nucleus is used in replication (through mitosis and meiosis) via daughter cells to continue cell growth.
The right atrium receives blood returning from others parts of the body through the superior vena cava and the inferior vena cava.
Explanation:
The pathway of circulation begins in the right atrium which receives the carbon dioxide-rich deoxygenated blood returning through the systemic circulation.
The deoxygenated blood from regions superior to the heart, i.e., the head, neck, shoulder areas are collected through the superior vena cava and that from the parts inferior or lower to the heart like visceral organs, extremities, trunk, hip etc are brought through the inferior vena cava.
Both these venous systems (superior and inferior) fill the right atrium.
The right atrium then pumps the deoxygenated blood to the right ventricle via the tricuspid valve.
The right atrium is filled with blood during diastole.
As fas as i remember 20% of whole cell is RBC
so the answer is 2×10^13 !!
the only flying mammal is a Bat
