A mutation is a permanent change in the DNA sequence of a gene. This can be beneficial if the change gives a new function to or improves the function of that gene.
<span>The above is a definition. But one must really define "beneficial". Some regard it as beneficial if it helps the specific individual who has it. Others would think it beneficial if it produced some survival advantage that insured more descendents for that individual. </span>
<span>It is the difference between a mutation that allowed for greater athletic ability, but a decreased desire for offspring, versus a more moderate athletic enhancement, but a greater desire for offspring. </span>
<span>The small percentage of ways to improve an organism, versus the near infinite ways of harming the organism, mean that most mutations are not going to be beneficial. At best, they will be "inconsequential" - such as a new shade of eye color, or a mole on a section of your skin. </span>
The populist notion of "powers" that can come from mutations is wildly inaccurate. Even assuming a minor power like the ability to see infra red radiation would take thousands upon thousands of mutations over vast amounts of time. A mutation for blindness is far more likely.
<span>It should also be noted that the traditional model of evolutionary theory no longer applies to man. We don't allow changes in our environment, and without such changes, there is no need for one trait more than another to predominate. After all, it is irrelevent that a mutation might allow for greater speed in running, when everyone drives a car.</span>
<span>Animals have centrioles to form spindle fibers during prophase. The centriole divides cells. Plants do not have them because they have microtubules instead; they do not need centrioles. Plants are capable of forming a circular loop of microtubules around the future plane of division prior to prophase called the preprophase band, rather than centrosome. Basically- plants don't need it. They have a different way of cell division.</span>
Answer:
They are ammonia, urea, uric acid, and creatinine. All of these substances are produced from protein metabolism.
Metabolic waste is the left over products of both catabolism and anabolism. This waste includes salts, phosphates, sulfates, excess substances, and nitrogenous wastes like urea which are eliminated through urine.
The three observations that could help an individual in distinguising whether the organism is a fish or not is that it should live under water as fish can't survive without water, another thing is that it should laid eggs when it comes to giving birth because when it does not lay eggs but produces a living organism normally without an egg, it is considered to be a mammal and lastly, the appearance it possess such as having gils or fins.
Adrenaline
Nicotine is a substance that is addictive in nature commonly
found in cigarette, that affect the nervous system by binding to the receptors
in the brain and other part of the body. Atherosclerosis is the loss of
elasticity or thickens of arteries walls. However, nicotine increases the
release of neurotransmitter adrenaline into the blood which subsequently cause
the development of atherosclerosis.
