Answer:
it’s in spanish not sure many people will understand itb
Explanation:
<span>Ozone is simply a molecule consisting of 3 oxygen atoms, which reacts strongly with other molecules. Ozone is created in the stratosphere when high energy uv radiation causes on O2 molecule to split. The free oxygen atoms collide and react with other O2 molecules to form O3.</span>
Production is highest where the solar uv is the greatest eg near the tropics, but once created, the ozone is then circulated towards the poles by the atmosphere. The amount of ozone in the stratosphere can vary with location, season and even day to day climatic conditions.
<span>The process of ozone creation is what makes the O3 in the atmosphere very effective at shielding the Earth from harmful uv radiation, which can cause many biological problems, such as skin cancer. However, due to its high reactivity, the uv found in the tropospher at ground level can aslo be dangerous as a toxic pollutant which is harmful to plants and lung tissue, and is a major cause of smog.</span>
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....
Eukaryotic cells have been confronted throughout their evolution with potentially lethal plasma membrane injuries, including those caused by osmotic stress, by infection from bacterial toxins and parasites, and by mechanical and ischemic stress. The wounded cell can survive if a rapid repair response is mounted that restores boundary integrity. Calcium has been identified as the key trigger to activate an effective membrane repair response that utilizes exocytosis and endocytosis to repair a membrane tear, or remove a membrane pore. We here review what is known about the cellular and molecular mechanisms of membrane repair, with particular emphasis on the relevance of repair as it relates to disease pathologies. Collective evidence reveals membrane repair employs primitive yet robust molecular machinery, such as vesicle fusion and contractile rings, processes evolutionarily honed for simplicity and success. Yet to be fully understood is whether core membrane repair machinery exists in all cells, or whether evolutionary adaptation has resulted in multiple compensatory repair pathways that specialize in different tissues and cells within our body.
Cells Can Replicate Their DNA Precisely. Replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. DNA replication is one of the most basic processes that occurs within a cell.
