Answer:
It's important for a scientist to try to hold all variables constant except for the independent variable. If a control variable changes during an experiment, it may invalidate the correlation between the dependent and independent variable. When possible, control variables should be identified, measured, and recorded.
B. Gene expression is in them is similar to us but facilitates the use of bacteria in recombiant biotechnology and gene therapy.
We human have eukaryotic cells which have a devoloped nucleas whereas small bacteria have prokaryotic cells with no definite nucleus using more biotechnology. Other all are not true.