Answer:
The two main variables in an experiment are the independent and dependent variable. An independent variable is the variable that is changed or controlled in a scientific experiment to test the effects on the dependent variable. A dependent variable is the variable being tested and measured in a scientific experiment.
Answer:
Nucleotides are made up of a five carbon sugar such as ribose or deoxyribose and a group of phosphate with 1-3 phosphates
Reduction is the process by which eletrons are gained by an atom.
The charge of a proton is positive.
D: the composition of the materials that make up the planet