Eukaryotic cells do not have a nucleus. The nucleus is where DNA, your genetic material, is usually stored. Prokaryotic cells do not have a nucleus. The DNA just floats around the cell instead of staying in one designated area.
The temperature is the independent variable. The independent variable is the variable that the researcher can control. And the dependent variable will change because of the change of independent variable. In this question, the student controls the temperature(independent variable) to see wether the gender(dependent variable) will change due to the temperature.
A nuclear power plant will use nuclear energy to power the town. While nuclear energy is perhaps one of the most effective ways to provide power, a nuclear accident is very dangerous, and could destroy an environment and its organisms. There was a nuclear accident in Chernobyl, Ukraine, in the 1900s. people had to evacuate because of it.
