<span>Villi are hair-like structures covered with epithelial cells measuring 1.5 mm that line the mucous inner membrane of the small intestine. The epithelial cells of the villi contain microvilli and are responsible for the absorption of nutrients. Being so small and numerous, they effectively increase the absorptive surface area of the small intestine. When the surface area increases, this is the time they absorb the nutrients.
As for plants' root hair cells, they receive nutrients through osmosis. Root hair cells are adapted for this by having a large surface area to speed up osmosis. The absorbed water and minerals are transported through the roots to the rest of the plant where it is used for different purposes: It is a reactant used in photosynthesis.
As we can see, both of them utilize increasing their surface area.</span>
They are ineffective against viral infections because viruses can not be treated with antibiotics.
Cholera develops when the bacterial toxin prevents G-protein inactivation , which leads to the continuous production of cAMP.
Answer:
Every winter, Arctic sea ice grows around the pole, its frozen tendrils threading along northern coasts. Right now sea ice has just passed its peak coverage for the year, and will begin to shrink with the coming of spring. It’s a crucial time for polar bears, whose food supply is inextricably linked to sea ice.
And in recent decades, sea ice has been shrinking faster than ever. According to the National Snow and Ice Data Center, 2019 has the seventh-lowest sea ice cover in the Arctic since they began collecting satellite data 40 years ago.
This year “doesn't break any records, but it's the trend that matters,” says University of Alberta polar bear scientist Andrew Derocher. “The downward trend in Arctic sea ice across all months is the concern,” he says, and “now we wait to see what spring conditions bring.” (Read more about global warming’s link to polar bears.)
A cold spring allows ice to linger, giving polar bears easier access to one of their favorite foods: seals. A warm spring cuts short the availability of their food super-highway....
