1.
When humans burn fossil fuels, most of the carbon quickly enters the as carbon dioxide.
Correct Answer
B. AtmospHere
Explanation
When humans burn fossil fuels, most of the carbon quickly enters the atmosphere as carbon dioxide. This is because the combustion process releases carbon atoms from the fossil fuels, which then combine with oxygen in the air to form carbon dioxide. The carbon dioxide is then released into the surrounding environment, primarily the atmosphere. This process contributes to the increase in greenhouse gases in the atmosphere, leading to global warming and climate change.
2.
Which one of these does not add CO2 to the atmosphere?
Correct Answer
B. Planting trees
Explanation
Planting trees does not add CO2 to the atmosphere because trees absorb CO2 through the process of photosynthesis. During photosynthesis, trees take in CO2 and convert it into oxygen, releasing it back into the atmosphere. Therefore, planting trees actually helps to reduce the amount of CO2 in the atmosphere by acting as a natural carbon sink.
3.
What does not produce carbon dioxide?
Correct Answer
A. pHotosynthesis
Explanation
Photosynthesis is the process by which plants convert carbon dioxide and water into glucose and oxygen, using sunlight as the energy source. During this process, carbon dioxide is taken in by plants and converted into glucose, while oxygen is released as a byproduct. Therefore, photosynthesis does not produce carbon dioxide but actually helps in reducing its levels in the atmosphere.
4.
How do living organisms return carbon to the atmosphere in the carbon cycle?
Correct Answer
B. Decomposition and respiration
Explanation
Living organisms return carbon to the atmosphere in the carbon cycle through the processes of decomposition and respiration. Decomposition is the breakdown of organic matter by bacteria, fungi, and other microorganisms, which releases carbon dioxide back into the atmosphere. Respiration, on the other hand, is the process by which organisms use oxygen to break down organic molecules and release carbon dioxide as a byproduct. Together, these processes play a crucial role in maintaining the balance of carbon in the atmosphere.
5.
In the carbon cycle, producers take in the gas __
Correct Answer
A. Carbon dioxide
Explanation
In the carbon cycle, producers, such as plants, take in the gas carbon dioxide. This is because plants use carbon dioxide during photosynthesis to produce glucose and oxygen. Carbon dioxide is an essential component for the growth and development of plants, making it the correct answer in the given options. Oxygen is released as a byproduct of photosynthesis, while nitrogen and carbon monoxide are not directly involved in the carbon cycle.
6.
In what process is Carbon transformed into chemical energy?
Correct Answer
A. pHotosynthesis
Explanation
Photosynthesis is the process by which carbon is transformed into chemical energy. During photosynthesis, plants use sunlight to convert carbon dioxide and water into glucose and oxygen. This glucose is then stored as chemical energy in the form of carbohydrates, which can be used by plants and other organisms for energy. Respiration, on the other hand, is the process by which organisms release energy from glucose, and primary and secondary production are terms used to describe the production of organic matter by plants and the consumption of this organic matter by animals, respectively.
7.
The main human activity that releases greenhouse gases is
Correct Answer
C. Burning fossil fuels
Explanation
Burning fossil fuels is the main human activity that releases greenhouse gases. Fossil fuels such as coal, oil, and natural gas are burned for energy production, transportation, and industrial processes. These combustion processes release carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) - the primary greenhouse gases contributing to climate change. The burning of fossil fuels is a significant contributor to the increase in greenhouse gas emissions, leading to global warming and environmental degradation.
8.
Why is the carbon cycle important?
Correct Answer
A. It continuously reuses and recycles carbon in the ecosystem
Explanation
The carbon cycle is important because it continuously reuses and recycles carbon in the ecosystem. Carbon is a vital element for all living organisms and is found in various forms, such as carbon dioxide and organic compounds. Through processes like photosynthesis and respiration, carbon is exchanged between the atmosphere, plants, animals, and the soil. This cycle helps maintain a balance of carbon in the environment, which is essential for the growth and survival of organisms. Additionally, the carbon cycle plays a crucial role in regulating Earth's climate by controlling the amount of carbon dioxide in the atmosphere.
9.
Why does too much carbon dioxide in the atmosphere cause climate change?
Correct Answer
C. It traps heat and warms up our planet
Explanation
Too much carbon dioxide in the atmosphere causes climate change because it acts as a greenhouse gas. When carbon dioxide levels increase, it creates a blanket-like effect, trapping heat from the sun within the Earth's atmosphere. This leads to a rise in global temperatures, causing the planet to warm up.
10.
Which of the following adds oxygen to the atmosphere?
Correct Answer
B. pHotosynthesis
Explanation
Photosynthesis is the process by which plants, algae, and some bacteria convert sunlight, carbon dioxide, and water into glucose and oxygen. During this process, plants release oxygen into the atmosphere as a byproduct. Therefore, photosynthesis is the correct answer as it adds oxygen to the atmosphere. Forest fires, on the other hand, release carbon dioxide and other pollutants into the air. The weathering of rocks and life processes of animals do not directly add oxygen to the atmosphere.