Question: Both biofuels and fossil fuels produce carbon dioxide (CO2) when burned/used. Does that mean they have the same impact on climate change?
Answer Options: Yes. In addition, biofuel production is just as damaging to the environment as is fossil fuel production. No. Fossil fuels release CO2 that prehistoric plants took out of the atmosphere a long time ago, adding to the total amount of CO2 in the atmosphere today, while biofuels release CO2 that was taken out of the atmosphere very recently, so do not increase levels of CO2 in the atmosphere overall. No, because the CO2 released by burning/using biofuels is cleaner than the CO2 released by fossil fuels. Yes. One reason is because biofuels are not as ‘green’ as some people make them seem. Correct Answer: No. Fossil fuels release CO2 that prehistoric plants took out of the atmosphere a long time ago, adding to the total amount of CO2 in the atmosphere today, while biofuels release CO2 that was taken out of the atmosphere very recently, so do not increase levels of CO2 in the atmosphere overall.
Question: “Biofuels have the potential to be ‘carbon neutral’, meaning that the plants/algae used to make them could consume as much carbon dioxide as the fuels emit when they are burned.” The preceding statement is…
Answer Options: True False Correct Answer: True
Question: How is bioethanol made?
Answer Options: It is made in the stems and leaves of corn plants. It is made by yeast using the process of fermentation. It is made by taking grains and malting them before extracting the ethanol. It is made by grinding up plants then boiling them and using a still to condense the alcohol out of the steam. Correct Answer: It is made by yeast using the process of fermentation.
Question: What are “dried distillers’ grains” and what is their importance to biofuels?
Answer Options: They are the grains used as the starting material for making bioethanol. Without them, we would not be able to make bioethanol. They are the form of grains that are stored over several years, to allow biofuels to be made even in years with bad harvests. They are the leftovers from making beer and other alcoholic beverages. They are then reused to make bioethanol. They are a co-product of the corn bioethanol process that are sold and used as a protein-rich animal feed. By providing extra revenue, they help make bioethanol from corn more economically feasible. Correct Answer: They are a co-product of the corn bioethanol process that are sold and used as a protein-rich animal feed. By providing extra revenue, they help make bioethanol from corn more economically feasible.
Question: “While there was concern that the use of corn for making biofuels was driving up the price of corn tortillas around the year 2007, the price increase was actually correlated with an increase in crude oil prices.” The preceding statement is…
Answer Options: True False Correct Answer: True
Question: If we used cellulosic bioethanol to replace fossil fuels, we could greatly reduce the overall amount of carbon dioxide we add to the atmosphere every year. Why then is cellulosic bioethanol not more popular and widespread?
Answer Options: When cellulosic bioethanol is burned/used, it produces ozone and methane, which are even more damaging to the atmosphere than carbon dioxide. We do not have a good supply of cellulosic material. It is challenging to extract sugars from cellulosic biomass because it is hard to break down plant cell walls, which have to be strong enough to support a plant/tree. At this point, we haven’t been able to make this process economically viable. When cellulosic biomass is used to make biofuels, it typically competes with the use of the same crops as food and feed. Correct Answer: It is challenging to extract sugars from cellulosic biomass because it is hard to break down plant cell walls, which have to be strong enough to support a plant/tree. At this point, we haven’t been able to make this process economically viable.
Question: Dedicated energy crops are crops that could be grown solely to be used to make biofuels, and not food/feed. Which of the following is a true limitation or benefit of using them in the United States?
Answer Options: They require a lot of plowing, weeding, and fertilizing and so farming them produces more carbon dioxide than they remove from the atmosphere when they’re growing. They are all annual plants, meaning they would have to be planted again each year. They are used to produce bioethanol, which will not be able to provide all our energy needs or replace fossil fuels completely. Energy cane is a particularly important dedicated energy crop in the USA because it can be grown in the arid western states, where few other crops can be grown. Correct Answer: They are used to produce bioethanol, which will not be able to provide all our energy needs or replace fossil fuels completely.
Question: Which of the following is a true benefit or drawback/challenge of algal bio-oil?
Answer Options: Algae are semi-transparent, so sunlight can penetrate through the cells and into the cells below those in the top layer of water. This allows for efficient photosynthetic productivity. Like bioethanol, bio-oil can only be used in specially modified engines, so its use is limited. One of the challenges we face in using bio-oil from algae is that it takes a lot of energy to extract the oil from the algae cells. Correct Answer: One of the challenges we face in using bio-oil from algae is that it takes a lot of energy to extract the oil from the algae cells.
Question: “Biofuels will be more competitive, economically, when fossil crude oil prices drop.” The preceding statement is…
Answer Options: True False Correct Answer: False
Question: Which of the following statements about biofuels is UNTRUE and was thus not discussed in the video, “Why don’t we have functional biofuels yet?”
Answer Options: “2nd generation” bioethanol was designed to address some of the problems associated with corn-based bioethanol. The United States has been quite successful in its recent attempts at making bioethanol from sugarcane at a large scale. Transesterification is a process used to turn used grease and oil from the restaurant industry into biofuel. Algae populations grown in open ponds to produce bio-oil are at risk of ‘attack’ by predatory bacteria and viruses. Correct Answer: The United States has been quite successful in its recent attempts at making bioethanol from sugarcane at a large scale.
Question: Which of the following statements best captures the interest in biofuels in the United States over time, as discussed in this course?
Answer Options: The popularity of biofuels peaked during the 1970’s energy crisis and has gone down steadily since then. The interest in biofuels has gone down over time, as more sources of fossil fuels have been identified in the United States with the increase in fracking. Interest in developing and producing biofuels has varied over time, with the peak amount of interest in biofuels historically occurring when crude oil prices have been high. Biofuels have become more popular each year, as the risks and scale of climate change become better known. Correct Answer: Interest in developing and producing biofuels has varied over time, with the peak amount of interest in biofuels historically occurring when crude oil prices have been high.
Question: “Biofuels have the potential to be ‘carbon neutral’, meaning that the plants/algae used to make them could consume as much carbon dioxide as the fuels emit when they are burned.” The preceding statement is…
Answer Options: True False Correct Answer: True
Question: Can bioethanol replace fossil fuels completely in the United States?
Answer Options: Yes, as soon as we figure out how to make it at large scale. No. While bioethanol can be used as a replacement fuel (in modified engines), it cannot be used as a replacement source of other substances we normally derive from petroleum, such as plastics. Yes. We are on track for this to happen by 2035. No, because we cannot produce it in the United States due to environmental regulations. Correct Answer: No. While bioethanol can be used as a replacement fuel (in modified engines), it cannot be used as a replacement source of other substances we normally derive from petroleum, such as plastics.
Question: How can added enzymes make the process of making bioethanol from corn more sustainable, as discussed in this course?
Answer Options: Amylases can provide a gentler and safer method to prepare the corn for bioethanol production, compared to the conventional method of using sulfuric acid. Enzymes reduce the cost of bioethanol production from corn by 40%, making it cost-competitive with synthetic ethanol production. Enzymes speed up the chemical reaction that makes bioethanol; without the addition of enzymes to the bioreactor as this step, bioethanol would not be made. The addition of lipases and proteases instead of DATEM and acid means that the bioethanol can also be used for food and beverage applications, and not just as fuel. Correct Answer: Amylases can provide a gentler and safer method to prepare the corn for bioethanol production, compared to the conventional method of using sulfuric acid.
Question: “The use of corn for making biofuels was the single biggest driver of the increase in the price of corn tortillas around the year 2007.” The preceding statement is…
Answer Options: True False Correct Answer: False
Question: In creating Dolly, scientists were careful to choose two different breeds of sheep to use in the process. What did they have to be careful about, as discussed in the course?
Answer Options: The egg donor had to be the same breed as the somatic cell donor, otherwise the DNA would not have been compatible. It was important to find a sheep to act as Dolly’s surrogate mother that was of the same breed as the somatic cell donor, otherwise the pregnancy would not have been possible. Correct Answer: It was important to find a sheep to act as Dolly’s surrogate mother that was of the same breed as the somatic cell donor, otherwise the pregnancy would not have been possible.
Question: “Dolly was not the first animal that was ever cloned; before she was created, other animals had been cloned through a different process called embryo splitting.” The preceding statement is…
Answer Options: True False Correct Answer: True
Question: How do scientists hold the cells still while they are performing SCNT?
Answer Options: They hold the cells with small tweezers. They place the cells in slight depressions (bowls) on a glass surface. They do not need to hold them because the cells are statically attracted to the glass needle used to manipulate the cells. They apply slight suction on the cell through a holding pipette. Correct Answer: They apply slight suction on the cell through a holding pipette.
Question: “While some people have claimed to have cloned a human, these reports have never been verified by the scientific community.” The preceding statement is…
Answer Options: True False Correct Answer: True