Answer:
The cell membranes are <u>Selectively permeable</u> or <u>semi-permeable.</u>
Explanation:
The cellular membrane allows the free passage of only a few substances while it blocks the pass of others.
Cellular membranes are <em>composed mostly of lipids arranged with their hydrophilic polar heads facing the exterior and the interior of the cells, while their hydrophobic tails are against each other</em>, constituting the internal part of the membrane.
Through this lipidic bilayer, some molecules can move from one side of the cell to the other. This free movement is called simple diffusion, and it depends on the substances' sizes and their concentration on each side of the membrane.
The membrane is selectively permeable because it only let small substances to move through it, with no protein mediating their passage.
<span>
D, because if white cattle are rr and red cows are RR, then roan cattle
are Rr. Therefore, a cross of Rr x RR would result in half RR and half
Rr.</span>
Answer:
Evolution is a gradual change in the inherited traits of a population over many generations. Natural selection is a mechanism where the members of a population best suited to their environment have the best chance of surviving to pass on their genes.
Less tilling thanks to genetically modified herbicide-tolerant crops also means that farmers spend less time on their tractors, using less fuel and reducing carbon emissions. Conservation tillage enabled by genetically modified crops has reduced greenhouse gas emissions on farms globally and can help farmers adapt to and mitigate climate change. In fact, in 2014 5.2 billion pounds of atmospheric carbon dioxide emissions were reduced by conservation tillage and decreased fuel use made possible by genetically modified crops. That’s equal to removing nearly 10 million cars from roads for one year.
According to the USDA, adopting conservation tillage can save at least 3.5 gallons of fuel per acre for farmers who would spend less time on their tractors, reducing emissions. If all of the corn planted in the U.S. (non-genetically modified and genetically modified combined) in 2015 was grown with conservation tillage methods, nearly 308 million gallons of fuel would be saved, equivalent to preventing 6.9 billion pounds of carbon emissions.
this is y air is important