Which is a better choice at the grocery store: paper bag? Plastic bag? Or tissue bag? Explain your answer.The best choice at the grocery store is to bring a used bag. Paper bags, plastic bags, and tissue bags all have individual issues associated with their use. Paper bags come from a renewable source, and are biodegradable. Despite this, they require more energy to make and are less likely to be reused. Plastic bags are not biodegradable but consume less energy to be made than paper or tissue bags. Tissue bags are the highest energy consumptive option, but are more likely to last longer and therefore be reused. As such, a tissue bag brought from home would be the best option.
Use the library or internet to find:
An example of junk sciencehttp://junkscience.com/2016/05/study-zika-and-the-risk-of-microcephaly/ - describes how the small risk of microcephaly from the Zika virus is not measureable
An example of frontier sciencehttps://www.theguardian.com/science/2016/mar/18/excitement-grows-over-large-hadron-colliders-possible-new-particle-lhc - the efforts of the large hadron collider are an example of frontier science
An example of consensus sciencehttp://lifehacker.com/5684996/what-alcohol-actually-does-to-your-brain-and-body - the effects of alcohol on the brain and body are consensus science as they have been repeatedly tested and proven
Use the second law of thermodynamics to explain why many poor people in developing countries live on a mostly vegetarian diet?The second law of thermodynamics explains the effects of how energy is transferred or transformed, and as a result of this process more of the energy is lost. In terms of poor people in developing countries, there is a reason why they have a mostly vegetarian diet. Growing crops requires a certain amount of energy from sunlight and nutrients. Animals that are killed for eating are generally fed on crops or other plants, which requires the transferral of energy from the plant product to the animal. This extra step means that some energy is lost when raising animals for eating, making plant-based diets the more energy efficient and cheapest way of eating.
What would happen to an ecosystem if:
all its decomposers and scavengers were eliminatedremoving decomposers and scavengers from an ecosystem would mean that plants would not have any available sources of essential nutrients. It would also lead to an increase in dead matter and waste products.
all its producers were eliminated, orproducers capture sunlight energy and turn it into usable chemical energy for the consumers that rely on them. Without this, the consumers that rely on the producers would die as a result of the lack of energy available to them.
all its insects were eliminated? Could a balanced ecosystem exist with only producers and decomposers and no consumers, such as humans and other animals? Explain.The removal of insects from the ecosystem would have a wide variety of consequences. One of the major losses would be the pollination that insects provide, meaning that many plants would lose their reproductive ability.No, ecosystems require a diversity and balance. Without humans and other consumers, decomposers and scavengers would have to do all the work of the consumer, which would not be feasible in the long term.
Why do farmers not need to apply carbon to grow their plants but often need to add fertilizer containing nitrogen and phosphorus?Plants get nitrogen and phosphorus from the soil, which means that soil-based fertilizers are simply providing these nutrients to the plants through the usual mechanism. Plants get carbon from the air, which means that adding carbon to a soil-based fertilizer would not give carbon nutrients to the plant, as it comes from the process of respiration rather than from the soil like other nutrients.
A large number of fish are suddenly found floating dead on a lake. You are called in to investigate the problem. You find an abundance of phytoplankton and also lack of oxygen. Suggest a reason for the fish kill.The presence of phytoplankton suggests that agricultural fertilizers have likely entered the lake through run-off. When this happens, a phenomenon called phytoplankton bloom is common. The phytoplankton are benefiting from the fertilizers and are thus growing at a rate that is increased. Their presence on the surface of the lake, combined with the high respiration rate, this has caused a deficiency of oxygen in the lake, which has led to the high rates of dead fish. The phytoplankton is essentially limiting the amount of nutrients available for the fish to live.
What are the specific ways through which water pollutants enter the environment?There are a number of different ways that water pollutants enter the environment. The main way is through the dumping of sewage into water systems, which can occur through flushing toilets and other waste disposal systems. The second is through agricultural run-off, which occurs when large numbers of fertilizers are used in an area and they run into the local water systems. Nuclear waste pollution is usually a result of waste being dumped into the environment and therefore pollutes the water in that environment. There are other forms of chemical waste and waste water, which are generally discharged by companies into local water and therefore collect in larger bodies of water, causing pollution to the environment. Oil pollution is associated with oil slicks, in which carriers transporting oil spill their contents into the ocean and thus kill marine animals within the area of the spill.
