B, a nucleus. Nuclei are membrane-bound organelles inside eukaryotic organisms. Eukaryotes are protists, fungi, plants, and animal cells. A bacteria is not a eukaryote, it is a prokaryote, so it does not have the membrane-bound structure of the nucleus.
Be careful, though, bacteria still have DNA. It is simply located in the center of the cell and is not encased in a membrane.
Answer:
As the variables are not given, let us help with general explanation on manipulated variable.
Explanation:
A manipulated variable is an independent variable. In a scientific experiment, an independent variable can be described as a variable which can change naturally or which is changed by the researcher to check its effect on the dependent variable. The dependent variable is the variable which is under study and being tested.
For example, to check the difference in photosynthesis rate by light, the amount of light will be the independent variable and the rate of photosynthesis will be the dependent variable.
