The U.S. Environmental Protection Agency said Wednesday that the average fuel economy of 2015 model-year vehicles increased 0.5 mile per gallon to a record high of 24.8 miles per gallon. Mazda had the highest average fuel economy of 29.6 mpg, the EPA said. Fiat Chrysler had the lowest, at 20.8 mpg. Most manufacturers improved over 2014, but General Motors Co. and Toyota Motor Corp. both had lower fuel economy in 2015 because they produced more trucks. Weight loss is one reason that fuel economy is increasing.
Prokaryotes and eukaryotes both have a plasma membrane. Prokaryotes also have a cell wall. Some eukaryotes also have cell walls, including plant cells and fungi. Prokaryotes and eukaryotes both have a plasma membrane. Prokaryotes also have a cell wall. Some eukaryotes also have cell walls, including plant cells and fungi.
Unlike eukaryotic cells, prokaryotic cells do not have a cell nucleus or any membrane-bound organelles such as mitochondria. Therefore neither the DNA of prokaryotic cells nor any of the sites of metabolic activity within a prokaryotic cell are enclosed by a separate membrane.