Answer: Experiment.
Explanation:
Suppose that we have two related variables, A (independent) and B (dependent)
We could design an experiment where we can manipulate the value of A at will, and we also can observe how the variable B changes.
This is called an experiment, where the objective is to see how the variable B is related to the variable A, and then try to make a model that explains this relationship.
If the Na+ voltage-gated channels in a muscle cell open, the Na (sodium) ions rush inside the muscle cell and makes the cell more positive as Na ions carry positive charge on it. Due to the entry of positively charged ions inside the cell, the cell becomes less negative and more positive. This is called depolarization of cell.
Answer: A = nucleus, B = plastids , C = ribosomes , D = cytoplasm
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Having attached earlobes is their phenotype. their genotype are the alleles that code for that