Answer:A) Nitrogen
Explanation: nitrogen cycle ensures the movement of nutrients through the biosphere.it ensures that nitrogen is constantly reused and made available.
Nitrogen gas is available in the atmosphere but plants and animals cannot use it in that form.it must be converted to compounds such as ammonia or nitrate.
It is gotten from the atmosphere during rainfalls where it Is broken down and combines with oxygen to from nitrogen peroxide.
Nitrogen can also be fixated into ammonia by saprophytic bacteria.
Also when plants die their body tissues are broken down to form ammonia.ammonia can be oxidized into nitrates and nitrite which plants can use.
Nitrites can be released back into the atmosphere through denitrifying bacteria and the cycle continues.
Answer:
D
Explanation:
there are around as many bacteria cells as there are human cells in the human body.
<span>The bone with insufficient or abnormal collagen would fracture easily compared with a healthy bone. Collagen is the most abundant protein in our bodies , and is found in muscles, bones, skin , blood vessels, digestive system and tendons. Collagen provides integrity, firmness and elasticity to their structures, such as bones. Therefore a healthy bone has high integrity and firmness and thus can resist fractures and other mechanical damages.</span>
Answer:
Carbon dioxide (CO2) and water (H2O)