The answer is 3. Since disposable products are mostly made up of plastic, and plastic also takes a hundred years before it can be completely degraded, the disposal of these plastic or solid waste could cause great harm in the environment.

3

The answer is 2. Modern agricultural methods have created serious insect problems because this method produce or grow crops that are located only one place, thereby making it easy for insects to easily damage or consume these crops.

2

The answer is 3. Since predators prey on those animals below the food chain, disrupting it would cause a significant decrease also of predators due to their lack of food resource.

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The answer is 2. Cycling of elements such as carbon dioxide and oxygen are needed for our daily needs. Interfering with this could cause harm to our environment as well as alter its natural course.

2

The answer is 3. Developing stronger and more effective pesticides can have a positive effect on the products used for it but could also affect the environment by producing harm to other organisms.

3

The answer is 1. By keeping in check by natural enemies, the normal homeostasis could be achieved. The normal amount in number of the beetles can be kept in a normal number.

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The answer is 3. Since they were just introduced there and is not naturally reproduced there, they do not have enemies against it therefore, having the chance to reproduce and live there successfully.

3

The answer is 4. The constant research regarding the preservation of certain plant and animal species has been of great help in maintaining the preservation of endangered species.

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The answer is 4. With regards to toxins, the higher that it is consumed in a food chain, the greater the toxin accumulated. As the toxin transfers from 1 level to a higher level, a greater amount of toxin is accumulated.

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The answer is 3. As technology arises, certain researches help in battling disease, how to handle them and how to prevent them thereby, increasing the life expectancy as the years go by.

3

The answer is 2. Renewable energy is defined as the energy which can be replaced or used again for other purposes. This kind of energy is recycled.

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The answer is 2. If we pass laws to regulate how fur hunters hunt down otters, sea urchin would also be regulated. The population of sea urchin would be decreased or balanced if sea otters were still regulated.

2

If grizzly bears are to be eliminated, there could be an imbalance in both the ocean and forest. Grizzlies have a major role in maintaining homeostasis in both ocean and forests. If they are removed, there would be an overpopulation of salmon and the forests would not be able to have nutrient rich soil which are brought about by the feces and decaying salmon made by the grizzlies.

The answer is 4. A keystone species is an organism having a great responsibility in the ecosystem. Without the keystone species, the ecosystem would not function or would not exist

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The answer is 1. According to the passage, otters, were the ones that were affected by humans. After humans hunted down sea otters, sea urchins became overpopulated and then kelp and fish were soon affected also.

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The answer is 3. Food becomes a limited factor when the time that a population increases. With limited food resources, the population becomes limited also.

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The answer is 4. The rate of population growth is greatest at point D. A seen in the graph, point D showed the highest point in the graph.

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The answer is 3. The point at which the mouse population be the greatest in the ecosystem would be at point C. This is the point wherein there is a constant increase in population number after being introduced.

3

The growth rate would be the same for both, they would both increase. But their difference is that in the growth rate of mouse in an abandoned field, it would be higher than those in a human population because in the human population, there would be competition as well as predators that could limit their population growth.

The answer is 3. According to the data given, the table correlates with the graph shown in choice 3. It is directly proportional. As the age of the population in hours increases, the number of protists in the population also increases.

3

The answer is 3. In the present time, the growth of the human population is resembled to the graph in choice 3.

3

Nitrate pollution in the brook changed after being deforested because deforestation decreases the amount of nitrogen circulating in the environment. This is due to the increase in carbon dioxide after being deforestation.

The cutting down of trees increases carbon dioxide because with too much carbon dioxide being exhaled by living organisms, with not enough trees to absorb it. Due to this effect, nitrogen decreases.

The change in carbon dioxide or the increase in carbon dioxide, increases the temperature thereby contributing to climate change or global warming.

One way in which humans have contributed to the increase in atmospheric carbon dioxide is by investing in new technologies that promote a newer and easier to produce products but have consequences to the environment.

One specific negative effect of an increase in temperature would be the depletion of the ozone, which in turn concentrating the heat towards melting of the ice caps.

One way humans could try to reduce global warming would be to decrease the pollution by avoiding lighting up plastic or making sure your car is maintained enough to reduce pollution in the air.

One reason that the loosestrife would probably out-compete the cattails is because these loosestrifes are foreign and was only introduced to the swamp, the presence of predators that eat these plants are not yet present.

Loosestrife plants would be the reason for the decrease in other organisms is because as time goes by, without the presence of predators, they would become overpopulated, dominating the place they were introduced to.

A way in which destruction of forest in South America could affect a hospital patient is by the spread of disease.Since the destruction of forests, leads to the lost of habitat for some animals, the diseases carried by these animals are brought to some parts of the city thereby causing disease.

Biodiversity is composed of different biotic and abiotic forms forming different ecosystems. It is a form of measurement for the different genes, species and the ecosystem.

If biodiversity is lost, there would be a decrease in population size as organisms would be vulnerable to predation and extinction and the loss of the ability to adapt to new changes.

One practice that could preserve the diversity in New York is to prevent destruction of habitats and avoid the need for new adaptation for the animals or organisms.

The amount of UV radiation may be increased in the surface because these are the location wherein the ozone becomes decreased due to the fact that as the stratosphere decreases, the ozone also depletes.

The effect of UV radiation for plankton is that the amount of UV absorbed by the plankton may become consumed by the primary consumers in the sea and may be carried onto or transferred to the next level of the food chain.

Since the ozone has been progressively depleting,, cooperation is needed because restoring the ozone may be impossible but can be maintained and can never be more worst.

The water plant contains DDT because it was absorbed by the water plant. The insecticide DDT is a poisonous chemical that is used to kill mosquito or malaria and other pests that could damage crops or swamps.

The amount of DDT pesticide is increased in the three bird species because the level of pesticide also increases as the level of the food chain also increases.

Two health problems that can be encountered living near the waste recycling plant would be lung cancer and bacterial infections. Lung cancer maybe because of the inhaled products from recycled plastic and bacterial infection may be from the handling of waste materials.

One cause of a health problem like lung cancer may be from inhaling the chemicals released from recycling plastics or other waste products.

One ecological benefit of recycling wastes is the decreased need to harvest products for making new products, instead, those materials which are already manufactured, can be used again.

Two advantages of using this type of way to reduce aphids is avoidance of using chemicals as pesticides and the introduction of a new diversity in the ecosystem.

Two possible dangers of using this method is the possibility of overpopulation due to the fact that they will not have enemies to keep them regulated and the risk of drawing other organisms away from their natural habitat.

One short term economic benefit of deforestation would be the availability of wood for the usage of manufacturing products for the growth of the economy.

Deforestation decreases biodiversity by decreasing their chance of survival. Deforestation open the chance to take away an organism or an animal’s natural habitat.

The cutting down of trees increases carbon dioxide because with too much carbon dioxide being exhaled by living organisms, with not enough trees to absorb it. Due to this effect, nitrogen decreases.

Since zebra mussels were accidentally introduced to the lake, the population of it could increase rapidly since they do not have predators that would stop them from reproducing.

Zebra mussels when overpopulated, can decrease the amount of oxygen in its habitat thereby affecting other aquatic animals in the water.

If many organisms become decayed, the amount of released hazardous wastes from the decaying bodies could affect the environment as well as those living also in that habitat.

The size of the population of zebra mussels would decrease after an initial increase because the food becomes limited for the increased population. The competition becomes tighter causing death for those who cannot compete.

The relationship between carbon dioxide and time is that carbon dioxide may have an increase and decrease in trend every year.

Carbon dioxide is decreased because of the time of carbon dioxide to be recovered before it can be able to serve again its function in the ecosystem.

The decrease in carbon dioxide may be due to the decrease also in temperature. Carbon dioxide, when accumulated, increases heat in the atmosphere.

Two processes that may lower carbon dioxide levels include the prevention of burning of fossil fuels and the decrease in smoke emissions produced by cars or factories.