The hemoglobin holoenzyme (active enzyme) is a complex of an iron ion and 4 subunits- 2 hemoglobin alpha and two hemoglobin beta. People with sickle cell disease have mutated beta hemoglobins. The mutation is a single nucleotide exchange, that changes the 6th amino acid of protein primary struture - a Glutamic acid into Valine. This one alteration changes the tree dimentional structure of hemoglobin beta so, that it forms lond fibres that disrupt the normal circular form of the red blood cells.
The answer is greenhouse gases
Most of the worlds deserts are located at latitudes where cold, dry air moving toward the poles descends.
E) cold, dry air moving toward the poles descends.
<u>Explanation:</u>
A large portion of the world's deserts are situated almost 30 degrees north scope and 30 degrees south scope, where the warmed tropical air starts to drop.
Hot deserts are essentially found around the Tropics of Cancer and Capricorn. As air moves inland, it gets drained of dampness and precipitation drops. So the majority of the world's deserts are situated at scopes where cool, dry air advancing toward the shafts slides.
I believe that last one is true (photosynthesis of plants)
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