Answer:
Without an oxygen atmosphere very few things could live on the early Earth. Anaerobic bacteria were probably the first living things on Earth. The early Earth had no oceans and was frequently hit with meteorites and asteroids.
Explanation:
Antibiotic used include kenamycin, ampicillin and tetracycline. This is useful to determine if and which bacteria took up the plasmid as they were supposed to during the process of recombination. Host bacteria are normally killed by these antibiotics. If the recombinant plasmids were taken up by the bacteria, plasmid may have contained a DNA gene for resisting the effects of one or more antibiotics. Host bacteria are placed in a growth medium containing an antibiotic to which they have a resistant gene in their recombinant plasmid DNA survivor. If they havent taken the plasmid they die.
When exercise does not increase bone mass, it has been observed that the risk of bone fractures increases due to osteoporosis.
<h3>What are the benefits of exercise to bone mass and density?</h3>
Bone mass refers to the mass of the bones in a living organism as a result of the deposition of minerals within the bone.
An increase in bone mass is directly related to the strength of the bone.
Strong bones have high bone masses whereas weak bone have low bone mass.
Physical activity have been shown to improve bone mass by increase the mass of deposited minerals in the bone.
Exercise such as walking, running, jogging, and other forms of exercise have been shown to improve bone mass and hence, the strength of bones.
However, when exercise does not increase bone mass, osteoporosis is observed which results in bone fracture.
In conclusion, the strength of a bone is directly related to the bone mass which is directly related to the mass of minerals deposited within them.
Learn more about bone mass at: brainly.com/question/10561482
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Many scientists agree that the universe is about 13 billion years old.
