Answer: More than 99 percent of all organisms that have ever lived on Earth are extinct. As new species evolve to fit ever changing ecological niches, older species fade away. But the rate of extinction is far from constant. At least a handful of times in the last 500 million years, 75 to more than 90 percent of all species on Earth have disappeared in a geological blink of an eye in catastrophes we call mass extinctions.
Though mass extinctions are deadly events, they open up the planet for new forms of life to emerge. The most studied mass extinction, which marked the boundary between the Cretaceous and Paleogene periods about 66 million years ago, killed off the nonavian dinosaurs and made room for mammals and birds to rapidly diversify
Answer:
Its D. role of carbon dioxide in photosynthesis.
Explanation:
I know its right bc I just got that question.
d is correct answer of a question
Answer:
The correct answer would be levodopa/carbidopa.
Tolcapone is a drug used as an adjunct to levodopa/carbidopa combination medication.
These drugs are used to treat the symptoms of Parkinson's disease.
Tolcapone is used to inhibit enzyme COMT (catechol-O-methyl transferase).
In the brain, levodopa is converted into dopamine which helps in controlling the movement.
Carbidopa helps in preventing the breakdown of levodopa in the blood which allows more levodopa to enter the brain. In addition, it helps in reducing the side-effects associated with levodopa such as vomiting, nausea et cetera.
Gout is a complex form of arthritis which is caused by a build up of uric acid. The particular patient population that is always affect is those who have high quantity of uric acid in their blood. The common cause of this medical condition is excess amount of uric acid that is present in the blood. The condition is characterized by severe pain,inflammation, redness and tenderness of joints.
