Answer:
Main sequence stars fuse hydrogen atoms to form helium atoms in their cores. About 90 percent of the stars in the universe, including the sun, are main sequence stars. These stars can range from about a tenth of the mass of the sun to up to 200 times as massive.
Stars start their lives as clouds of dust and gas. Gravity draws these clouds together. A small protostar forms, powered by the collapsing material. Protostars often form in densely packed clouds of gas and can be challenging to detect.
"Nature doesn't form stars in isolation," Mark Morris, of the University of California at Los Angeles (UCLS), said in a statement. "It forms them in clusters, out of natal clouds that collapse under their own gravity."
Smaller bodies — with less than 0.08 the sun's mass — cannot reach the stage of nuclear fusion at their core. Instead, they become brown dwarfs, stars that never ignite. But if the body has sufficient mass, the collapsing gas and dust burns hotter, eventually reaching temperatures sufficient to fuse hydrogen into helium. The star turns on and becomes a main sequence star, powered by hydrogen fusion. Fusion produces an outward pressure that balances with the inward pressure caused by gravity, stabilizing the star.
How long a main sequence star lives depends on how massive it is. A higher-mass star may have more material, but it burns through it faster due to higher core temperatures caused by greater gravitational forces. While the sun will spend about 10 billion years on the main sequence, a star 10 times as massive will stick around for only 20 million years. A red dwarf, which is half as massive as the sun, can last 80 to 100 billion years, which is far longer than the universe's age of 13.8 billion years. (This long lifetime is one reason red dwarfs are considered to be good sources for planets hosting life, because they are stable for such a long time.)
Explanation:
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Answer:
A
Explanation:
Somatic cells are diploid (46 chromosomes)
Gamete cells are haploid ( 23 chromosomes)
<span>This is called an epidural. A procedure that delivers continuous pain relief to the lower part of your body while allowing women to remain fully awake. It decreases sensation of pain. The medication is inserted into the epidural space just outside the spinal cord and spinal fluid. This is the most common method used in the United States.</span>
Answer:
C. Ethanol, ammonium chloride, phosphate buffer, magnesium sulfate, calcium chloride, trace elements
Explanation:
Acetobacter must have a sufficient supply of oxygen and cannot grow in its absence. Colonies of acetobacter can be detected by a culture media containing ethanol as carbon source, the acid produce by the bacteria will dissolve the chalk thereby leaving a clear zone around the colony.
Answer:
Explanation:
<h2>
Homotropic effector-</h2>
<h2>Both -</h2>
The phrase 
is relevant and can be applied for homotropic effector molecules since the heterotropic effector molecules have the possibility and affinity to change the sigmoidal curve to a more potential hyperbolic curve contingent upon the allosteric effector to be positive or negative modulator.
The expression isn't relevant for both homotropic and heterotrophic effectors since the two of them can tie to the allosteric site of allosteric enzymatic compounds.
The phrase 
is significant and can be applied for both homotropic and heterotropic effectors.
The expression 
is significant and applied for homotropic effectors just as when substrate molecules tie to the allosteric site of enzyme then it is regarded as homotropic effectors. The heterotropic effectors are effectors apart from substrate molecules.
The phrase 
is not applied and insignificant to none of the heterotropic or homotropic effector molecules since 
is significant for the enzymes that obey the Michaelis-Menten equation, but allosteric enzymes do not obey the Michaelis-Menten equation. Homotropic and heterotropic effectors are viable and efficient for allosteric enzymatic chemicals that don't contain
