1.
What percent of the earth's surface is covered by forests?
Correct Answer
D. 31 percent
Explanation
Approximately 31 percent of the earth's surface is covered by forests. This means that almost one-third of the planet is filled with trees and vegetation. Forests play a crucial role in maintaining biodiversity, regulating climate, and providing resources for humans and wildlife. They are essential for the health of the planet and the well-being of all living organisms.
2.
Which of these is not a result of deforestation?
Correct Answer
D. Biosequestration
Explanation
Biosequestration refers to the process of capturing and storing carbon dioxide from the atmosphere through natural or artificial means. It is not a result of deforestation, but rather a potential solution to combat climate change. Deforestation, on the other hand, leads to aridity (drying out of the land), biodiversity loss (destruction of habitats and species), and habitat damage (disruption of ecosystems).
3.
What is the direct cause of deforestation?
Correct Answer
C. Agriculture
Explanation
Agriculture is the direct cause of deforestation. This is because large areas of forests are cleared to make way for agricultural activities such as farming and livestock grazing. The demand for agricultural land leads to the clearing of trees, which results in deforestation. This is a major driver of deforestation globally, as forests are cleared to create space for crops and livestock, causing the loss of biodiversity and disruption of ecosystems.
4.
Which of these is not a cause of contemporary deforestation?
Correct Answer
A. Reforestation
Explanation
Reforestation is not a cause of contemporary deforestation because it refers to the process of planting trees to replace those that have been cut down or lost. It is a deliberate effort to restore and increase forest cover, thus countering deforestation. In contrast, urbanization, overpopulation, and population growth are all factors that contribute to deforestation by increasing the demand for land and resources, leading to the clearing of forests for agriculture, infrastructure, and settlement purposes.
5.
Which of these is affected by deforestation?
Correct Answer
B. Water cycle
Explanation
Deforestation affects the water cycle. Trees play a crucial role in the water cycle by absorbing water from the soil through their roots and releasing it into the atmosphere through a process called transpiration. When trees are cut down, this process is disrupted, leading to reduced water absorption and evaporation. As a result, there is less moisture in the air, leading to decreased rainfall and altered precipitation patterns. Deforestation also increases the risk of soil erosion, which further impacts the water cycle by reducing the amount of water that can be absorbed into the ground.
6.
Which of these refers to the variability and variety of life on Earth?
Correct Answer
C. Biodiversity
Explanation
Biodiversity refers to the variability and variety of life on Earth. It encompasses the different species of plants, animals, and microorganisms, as well as the genetic diversity within each species and the diversity of ecosystems. Biodiversity is important for maintaining the balance of ecosystems and providing various ecosystem services such as food, clean air and water, and climate regulation. It is also crucial for human well-being, as it supports agriculture, medicine, and tourism industries.
7.
What percentage of the world greenhouse gas emissions is caused by deforestation?
Correct Answer
A. 20 percent
Explanation
Deforestation contributes to approximately 20 percent of the world's greenhouse gas emissions. This is because trees store carbon dioxide, and when they are cut down or burned, the stored carbon is released into the atmosphere as carbon dioxide, a major greenhouse gas. The loss of trees also reduces the Earth's capacity to absorb carbon dioxide, further exacerbating the greenhouse effect. Therefore, deforestation plays a significant role in global warming and climate change.
8.
What percentage of the earth's fresh water does tropical rainforest produce?
Correct Answer
A. 30 percent
Explanation
Tropical rainforests produce approximately 30 percent of the earth's fresh water. This is because the dense vegetation in rainforests helps to absorb and retain water, which then evaporates and contributes to the formation of clouds and rainfall. The high levels of rainfall in these regions help to maintain the water cycle and supply fresh water to other parts of the world.
9.
Which of these is not a natural disaster?
Correct Answer
A. Fire accidents
Explanation
Fire accidents are not considered a natural disaster because they are typically caused by human activities, such as negligence or accidents. While fires can cause significant damage and loss of life, they are not considered natural phenomena like landslides, hurricanes, and earthquakes, which are caused by natural forces and occur without human intervention.
10.
Which of these continents has the highest rate of deforestation?
Correct Answer
C. Africa
Explanation
Africa has the highest rate of deforestation among the given continents. This is due to several factors such as population growth, expansion of agriculture, illegal logging, and urbanization. The demand for agricultural land, especially for cash crops like palm oil and soybeans, has led to the clearing of vast areas of forests. Additionally, weak enforcement of forest protection laws and limited resources for conservation efforts contribute to the high rate of deforestation in Africa.