Answer:

1.The two most common types of biofuel are bioethanol and biodiesel. ... Cellulosic biomass, derived from non-food sources, such as trees and grasses, is also being developed as a feedstock for ethanol production.

2.Replacing fossil fuels with biofuels—fuels produced from renewable organic material—has the potential to reduce some undesirable aspects of fossil fuel production and use, including conventional and greenhouse gas (GHG) pollutant emissions, exhaustible resource depletion, and dependence on unstable foreign suppliers.

3.The U.S. government considers biodiesel to be carbon-neutral because the plants that are the sources of the feedstocks for making biodiesel, such as soybeans and palm oil trees, absorb carbon dioxide (CO2) as they grow. The absorption of CO2 by these plants offsets the CO2 that forms while making and burning biodiesel.

4.Modified yeast could help make ethanol from hard-to-digest materials. Genes copied from a common fungus could simplify the production of ethanol from abundant materials such as grass and wood chips, a development that could one day help ethanol compete with gasoline.

Explanation:

1.bioethanol

2.potential to reduce some undesirable aspects of fossil fuel production and use,

3.absorb carbon dioxide (CO2) as they grow

4.Modified yeast