1.
Nitrogen that is used by plants is in the form of...
Correct Answer
B. Nitrates
Explanation
Plants use nitrogen in the form of nitrates. Nitrates are a type of nitrogen compound that plants can absorb and use for various biological processes, such as protein synthesis and growth. Nitrogen monoxide and oxygen are not directly used by plants in the same way as nitrates.
2.
What do plants do with the nitrogen they absorb?
Correct Answer
C. Build proteins
Explanation
Plants use the nitrogen they absorb to build proteins. Nitrogen is an essential nutrient for plants and is a key component of amino acids, which are the building blocks of proteins. Proteins play a crucial role in various biological processes, including growth, development, and defense mechanisms in plants. Therefore, plants utilize the absorbed nitrogen to synthesize proteins, ensuring their proper functioning and overall health.
3.
Animals absorb nitrogen through eating plants.
Correct Answer
A. True
Explanation
Animals absorb nitrogen through eating plants because plants are able to convert atmospheric nitrogen into a usable form called nitrate through a process called nitrogen fixation. Animals then consume these plants and obtain the nitrogen they need for various biological processes, such as building proteins and DNA. Therefore, it is true that animals absorb nitrogen through eating plants.
4.
Animals do not use nitrogen to build proteins.
Correct Answer
B. False
Explanation
Animals do use nitrogen to build proteins. Nitrogen is an essential component of amino acids, the building blocks of proteins. Animals obtain nitrogen from their diet, primarily in the form of protein-rich foods. Once ingested, the body breaks down proteins into amino acids, which can then be used to synthesize new proteins for growth, repair, and various biological functions. Therefore, the statement that animals do not use nitrogen to build proteins is false.
5.
When is ammonia released?
Correct Answer
A. The breaking down of dead animals by fungi and bacteria.
Explanation
Ammonia is released during the process of decomposition, which occurs when dead animals are broken down by fungi and bacteria. These microorganisms break down the organic matter of the dead animals, releasing ammonia as a byproduct. This ammonia can then be used as a source of nitrogen by other organisms in the ecosystem.
6.
What is the function of nitrifying bacteria?
Correct Answer
B. The conversion of ammonia into nitrates.
Explanation
Nitrifying bacteria play a crucial role in the nitrogen cycle by converting ammonia into nitrates. Ammonia is a toxic compound that can be harmful to many organisms, so the conversion of ammonia into nitrates is essential for the removal of ammonia from the environment. Nitrates, on the other hand, are less toxic and can be utilized by plants as a source of nitrogen for growth. Therefore, the function of nitrifying bacteria is to convert ammonia, which is a waste product, into nitrates, which can be further utilized by plants.
7.
Where are nitrogen fixing bacteria found?
Correct Answer
C. In the roots of plants.
Explanation
Nitrogen fixing bacteria are found in the roots of plants. These bacteria have the ability to convert atmospheric nitrogen into a usable form for plants, called nitrogen fixation. This process is important as it helps in the production of nitrogen-containing compounds, such as proteins and nucleic acids, which are essential for plant growth. By colonizing the roots of plants, these bacteria form a symbiotic relationship with the plants, providing them with a vital nutrient while receiving a source of energy from the plants in return.
8.
What is the primary role of the Nitrogen Cycle in ecosystems?
Correct Answer
C. Converting inert nitrogen in the atmospHere into a more usable form for living organisms
Explanation
The Nitrogen Cycle is a biogeochemical process that plays a crucial role in transforming inert nitrogen in the atmosphere into a more usable form for living organisms, particularly plants. Nitrogen is an essential nutrient for plants, but the abundant atmospheric nitrogen cannot be directly utilized by most living organisms without undergoing transformation through the Nitrogen Cycle.