Variation means difference in genetic makeup between individuals within a specie.
Answer: Biomass
Biomass produces gas or many sorts of waste products which are mostly used in burning and cooking. It is plant or animal material used as fuel to produce electricity or heat. Examples are wood, energy crops, and waste from forests, yards, or farms.
But the reason why it can be harmful is because biomass can produce gases like methane. Methane is a greenhouse gas which can harm the environment and reduce the ozone layer that stops harmful UV light from reaching the earth atmosphere.
The Lederberg experiment that used the technique of replica plating showed that mutations are random and are not a result of the needs of the organism.
<h3 /><h3>What is a random mutation?</h3>
Random mutations are just that, they are changes in the genome of an organism that arise randomly. These mutations are the backbone of evolution and natural selection in that when they arise, if the organism becomes more adapted to survival as a result of this mutation, it increases its odds of survival through natural selection.
Therefore, we can confirm that The Lederberg experiment that used the technique of replica plating showed that mutations are random and are not a result of the needs of the organism.
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All choices correctly describes physical barriers. Physical barriers after composed of tight junctions wherein it is difficult for the bacteria and viruses to penetrate. Examples of these physical barriers are the skin and the mucous membranes and these work in conjunction with secretions like tears and mucus (as tears and mucus contain IgA, a special type of immunoglobulin that is secreted to fight harmful organisms).
Gases such as water vapor and carbon dioxide that trap heat near earth are known as greenhouse gases.
