Energy in ecosystems must be continuously supplied by the sun as the warmth from the sun allows plants to grow plus photosynthesis depends on the sun's energy also. Animals also depend on the sun for warmth to survive (or else hibernate). Also, the sun powers the water cycle, the carbon cycle and the nitrogen cycle
Answer is D.
Waste products from metabolism are carried by the circulation to the kidneys, which filter them out if the blood to be excreted in urine.
<span>The minimal amount of nutrients needed every day by healthy people to prevent nutrient deficiencies is called the RDA.
RDA stands for recommended dietary allowances. </span>RDA's are established by the Food and
Nutrition Board of the National Academy of Sciences. There is a term RDI related to this. RDI stands for recommended daily intake.
Flu vaccines need to be revised and changed every year because the flu virus constantly mutates. Flu viruses can change in two ways: drift or shift. Antigenic drift occurs when genes of the virus slowly change during replication until the immune system no longer recognizes it. On the other hand, antigenic shift occurs when a major change in the virus happens. This usually leads to a totally different kind of virus. This is what happened during the H1N1 scare in 2009.
DNA viruses like mumps are less prone to mutation due to the presence of DNA polymerase. RNA viruses are more prone to mutation because they undergo reverse transcription to simulate the role of DNA.
Answer:
<em>True</em><em> </em><em>.</em><em> </em><em>I</em><em> </em><em>think</em><em> </em><em>it's </em><em>true</em><em>.</em><em> </em><em>hope</em><em> </em><em>this</em><em> </em><em>helps</em>
