1.
The movement of nitrogen between the environment and living things is called the
Correct Answer
A. Nitrogen cycle
Explanation
The nitrogen cycle refers to the continuous movement of nitrogen between the environment and living organisms. Nitrogen is an essential element for the growth and development of all living things, but it cannot be directly taken from the atmosphere by most organisms. The nitrogen cycle involves various processes such as nitrogen fixation, nitrification, assimilation, ammonification, and denitrification. These processes convert nitrogen into different forms that can be utilized by plants and other organisms. Through the nitrogen cycle, nitrogen is constantly recycled and made available for the growth of new organisms, ensuring the sustainability of ecosystems.
2.
The process in which bacteria in the soil change nitrogen gas into forms that plants can use is called
Correct Answer
A. Nitrogen fixation
Explanation
Nitrogen fixation is the process by which bacteria in the soil convert nitrogen gas into forms that plants can utilize. This process is essential for plants to obtain the necessary nitrogen they need for growth and development. Bacteria, such as Rhizobium, have the ability to convert atmospheric nitrogen into ammonia, which can then be further converted into other nitrogen compounds that plants can absorb through their roots. Nitrogen fixation plays a crucial role in maintaining the nitrogen cycle and ensuring a sustainable nutrient supply for plant growth.
3.
Why do organisms need nitrogen?
Correct Answer
A. To build up proteins, DNA, and new cells
Explanation
Organisms need nitrogen to build up proteins, DNA, and new cells. Nitrogen is an essential component of amino acids, which are the building blocks of proteins. Proteins play a crucial role in various biological processes, including cell structure, enzyme function, and immune response. Nitrogen is also necessary for the synthesis of DNA, the genetic material that carries the instructions for cell growth and reproduction. Additionally, nitrogen is an essential nutrient for the production of new cells, as it is required for cell division and growth.
4.
Name 2 things that perform most nitrogen fixation.
Correct Answer
A. Plant roots, bacteria in the soil
Explanation
Plant roots and bacteria in the soil are the two main sources of nitrogen fixation. Plant roots have specialized structures called nodules that house nitrogen-fixing bacteria. These bacteria convert atmospheric nitrogen into a form that plants can use for their growth and development. The bacteria in the soil also play a crucial role in nitrogen fixation by converting atmospheric nitrogen into a usable form for plants. Together, plant roots and soil bacteria contribute significantly to the nitrogen cycle and the availability of nitrogen for plant growth.
5.
How do plants get the Nitrogen the need?
Correct Answer
A. Plant roots take up nitrogen from the soil
Explanation
Plants get the nitrogen they need by absorbing it through their roots from the soil. Nitrogen is an essential nutrient for plant growth and is required for various metabolic processes. It is present in the soil in the form of nitrates and ammonium ions. The plant roots have specialized structures called root hairs that increase their surface area, allowing for more efficient absorption of nutrients, including nitrogen. Once absorbed, the nitrogen is used by the plant to synthesize proteins, enzymes, chlorophyll, and other essential components necessary for growth and development.
6.
How do animals get the nitrogen the need?
Correct Answer
A. From eating plants
Explanation
Animals obtain the nitrogen they need by consuming plants. Nitrogen is an essential component of proteins and other important molecules in the body. Plants, through the process of nitrogen fixation, absorb nitrogen from the atmosphere and convert it into organic compounds. When animals consume plants, they acquire these organic compounds and break them down during digestion, releasing the nitrogen for their own use. Therefore, animals rely on plants as a source of nitrogen to meet their nutritional requirements.