What's the answer please

What is the answer for the complicated molecules that make up living things usually contain carbon. why is carbon so important in these molecules?

Which of these serves as a reference for comparison during a scientific investigation? a)outcome variable (dependent variable) b) test variable (independent variable) c)control group d)hypothesis

All individuals have two alleles for a given trait. according to mendel's these alleles are passed down one each from both mother and father.