<span>Transfer of materials into a cell against a concentration gradient from low to high concentration requires active transport because you need energy for it to happen since its going againist the concentration gradient.
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A would be your answer! Have a great day love!
If each subunit of a hemoglobin protein molecule carries a heme group and a hemoglobin protein molecule is made of four subunits, two α and two β, we can simply multiply four (number of heme groups that can be found in one hemoglobin protein molecule) by three (number of hemoglobin protein molecules considered). 4×3=12
There are twelve heme groups in three hemoglobin protein molecules.
If in an eight-cell embryo of an organism, the cells of the upper tier are aligned over the cells of the lower tier at a slight angle, it is likely that the organism is a vertebrate.
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Ofcourse, <span>Cone-bearing plants</span>
