Nitrogen Cycle Questions

Correct! Burning fossil fuels, using synthetic nitrogen fertilizers, and cultivating legumes all fix nitrogen. Through these activities, humans have more than doubled the amount of fixed nitrogen that is pumped into the biosphere every year.

Bacteria play an important role in changing nitrogen when it gets to the soil. They are responsible for the process of nitrogen fixation, where they convert atmospheric nitrogen into a form that can be used by plants. This is a crucial step in the nitrogen cycle as it allows plants to obtain the necessary nitrogen for their growth and development. Reptiles, whales, and plants do not have the ability to change nitrogen in this way, making bacteria the correct answer.

Nitrification is the correct answer because it is the process in the nitrogen cycle that converts ammonium into nitrates. This process involves two steps: the first step is the oxidation of ammonium to nitrite by nitrifying bacteria, and the second step is the oxidation of nitrite to nitrate by different nitrifying bacteria. Nitrates are an important form of nitrogen that plants can easily absorb and use for growth, making nitrification a crucial step in the nitrogen cycle.

Microorganisms, particularly bacteria, play major roles in all of the principal nitrogen transformations. Nitrogen-fixing bacteria often form symbiotic relationships with host plants. In fact, most nitrogen-fixing is carried out by bacteria.

Although the majority of the air we breathe is N2, most of the nitrogen in the atmosphere is unavailable for use by organisms. In order for plants and animals to be able to use nitrogen, N2 gas must first be converted to a different form, such as ammonium (NH4+), nitrate (NO3-), or organic nitrogen.

The nitrogen in plants comes from the soil. Bacteria in the soil take nitrogenous wastes and convert it into forms of nitrogen that plants can use. Plants then take up nitrogen through their roots.

The atmosphere is the largest natural reservoir of nitrogen on Earth. Nitrogen makes up about 78% of the Earth's atmosphere and is crucial for many biological processes. It is an essential element for the formation of proteins and DNA in living organisms. Nitrogen is constantly cycled through the atmosphere, land, and water through various processes like nitrogen fixation, nitrification, and denitrification. The other options, such as the sun, ocean, and dirt, do not contain as much nitrogen as the atmosphere.

The chemical formula for nitrogen gas in the atmosphere is N2. This means that nitrogen gas consists of two nitrogen atoms bonded together. This formula is commonly used to represent the nitrogen gas that makes up about 78% of Earth's atmosphere.

Plants cannot utilize naturally occurring nitrogen gas because they are unable to break the triple bond between the two nitrogen atoms. Nitrogen gas is composed of two nitrogen atoms tightly bonded together, and plants do not possess the enzymes necessary to break this strong bond. Instead, they rely on nitrogen-fixing bacteria to convert nitrogen gas into a usable form, such as nitrate (NO3-), which can be taken up by plants and used for growth and development.

Ammonification is the process in the nitrogen cycle that converts dead plants and animals into ammonium. This occurs through the decomposition of organic matter by bacteria and fungi. During ammonification, these decomposers break down the proteins and other nitrogen-containing compounds present in dead organisms, releasing ammonium as a byproduct. This ammonium can then be further transformed into other nitrogen compounds through processes like nitrification and denitrification.

Approximately 78% of the air around us is made up of nitrogen gas, N2. Nitrogen is the most abundant gas in the Earth's atmosphere and is essential for many biological processes. This high percentage of nitrogen in the air is crucial for the survival of living organisms and plays a significant role in maintaining the balance of gases in the atmosphere.

Correct! In the process of denitrification, bacteria convert nitrate to dinitrogen (N2), a gas that is rapidly lost to the atmosphere.

Nitrogen fixation is the process in the nitrogen cycle where atmospheric nitrogen gas (N2) is converted into ammonia (NH3) or ammonium (NH4+). This conversion is carried out by nitrogen-fixing bacteria, which make nitrogen from the air available in a form that plants can use to synthesize proteins and other essential compounds. Denitrification (A) is the process where nitrates are converted back into atmospheric nitrogen gas, nitrification (B) is the conversion of ammonia into nitrite and nitrate, and nitrate assimilation (D) is the incorporation of nitrate into plant tissues.

Nitrogen fixation is the process that converts nitrogen gas (N2) into ammonium (NH4+), which is a form of nitrogen that can be utilized by plants and other organisms. This process is carried out by certain bacteria and archaea, either in the soil or in the root nodules of leguminous plants. These microorganisms have the ability to convert atmospheric nitrogen into a form that can be incorporated into organic compounds. Ammonification, on the other hand, is the process by which organic nitrogen compounds are converted into ammonium, while denitrification is the process that converts nitrate (NO3-) back into nitrogen gas.

After nitrogen is incorporated into organic matter, it is often converted back into inorganic nitrogen by decay. When organisms die, bacteria and fungi consume organic matter. During decomposition, a significant amount of the nitrogen contained within the dead organism is converted to ammonium.

Correct! In nitrification, some positively charged ammonium ions are converted to negatively charged nitrate. The positive charge prevents ammonium nitrogen from being leached out of the soil by rainfall. In contrast, the negatively charged nitrate ion is not held by soil particles and so can be washed out of the soil and into surface and groundwater.

Nitrogen is important for life on Earth because it is used to make DNA, chlorophyll in plants, proteins, and amino acids. DNA is the genetic material that carries the instructions for the development and functioning of all living organisms. Chlorophyll is the pigment that allows plants to photosynthesize and convert sunlight into energy. Proteins are essential for the structure, function, and regulation of cells, tissues, and organs. Amino acids are the building blocks of proteins. Therefore, nitrogen plays a crucial role in the fundamental processes of life and is necessary for the existence and functioning of living organisms.

Correct! Nitrogen (N) is an essential component of DNA, RNA, and proteins. In the process of nitrogen fixation, bacteria convert N2 from the atmosphere into ammonium, a form that plants and animals can use. The ammonia produced by nitrogen fixing bacteria is used to make protein.