<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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Answer:
The Rules of Protein Structure. The function of a protein is determined by its shape. The shape of a protein is determined by its primary structure (sequence of amino acids). The sequence of amino acids in a protein is determined by the sequence of nucleotides in the gene (DNA) encoding it.
A model organism is a species that has been widely studied to understand a particular biological phenomena, normally used because they are easy to breed and maintain in a laboratory setting and has certain experimental advantage.
The criteria that Thomas hunt Morgan was looking for include; the model organism should be small in size, easy to keep in the laboratory and also able to produce large number of off springs in a short time.
A. Osmosis. Hope this helps :)
