What is the function of heart valves?

Aresearcher is studying the science of attractiveness and asks volunteer test subjects to rank what trait they find most attractive in a person what type of variable is the dependent variable in this experiment

'which of these statements about the scientific method is not true? all experiments must follow the same number of steps in the procedure. experiments may be repeated several times. some unexpected results can be beneficial. experimental results may or may not support the hypothesis.

The chromosomal structure that limits the number of cell divisions of a cell is the the chromosomal structure that limits the number of cell divisions of a cell is the kinetochore telomere histones centromere