Earth had essentially no atmosphere when it originated 4.6 billion years ago from a heated mixture of gases and minerals. The ground had melted on it.
An atmosphere developed when Earth cooled, primarily from gases released by volcanoes. It contained methane, hydrogen sulfide, and ten to 200 times as much carbon dioxide as the atmosphere we are surrounded by today. The Earth's surface began to cool and solidify after roughly 500 million years, allowing water to accumulate there. Although life on Earth continued to develop and diversify, such periods of expansion and development were halted by mass extinctions, in which many of the planet's major life forms were either entirely or partially wiped out and many others were freshly established. Such catastrophic extinction episodes are attributed to asteroids impacts, climate change, volcanic eruptions, etc. Dinosaurs were also wiped out in one such event. The largest problem the Earth is currently experiencing is climate change brought on by human activity. Although human activities may exterminate some species from the world, the planet will undoubtedly recover and return to its natural balance as it has for millions of years. However, the sun will ultimately wipe out Earth, as predicted by scientists. The Sun will lose its structural integrity and enlarge in volume as it ages and eventually runs out of the fuel that keeps it going—hydrogen—which will cause it to burn everything in its path, including life on Earth. In the end, the Sun would perish, leaving the Solar System permanently in the dark.
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<span>prediction made by a researcher regarding a positive or negative change, relationship, or difference between two variables of a population</span>
An atmosphere is a layer of gas or layers of gases that envelope a planet, and is held in place by the gravity of the planetary body.
To send information from the brain or spinal cord to muscles and glands - is the purpose of motor neuron
Explanation:
As part of the central nervous system (CNS), the motor neurons connect the brain and spinal cord to all the muscles and glands present all over the body and innervates them.
Their main function is to transmit nerve impulses from the CNS to the muscles, both skeletal and smooth, and directly controls the movements of the muscles of the body.
A motor neuron is a typical nerve cell with multipolar body. It can be upper of lower motor neuron.
Right from snapping of fingers to movements of hamstrings, all muscular movements functions due to impulse carried by the motor neurons.
Degeneration of the motor neurons leads to neurodegenerative diseases like spinal muscular atrophy or amyotrophic lateral sclerosis.
