<span>Controlled variable is a variable that was made constant in the research. That was because the controlled variables can influence the dependent or independent variable. If the variables is not made constant, it can alter the research result and made it invalid.
In this case, </span>the caffeine and alcohol intake might alter the physical activity or the blood glucose so it should be controlled.
Explanation:
the answer is not A, B,D now get it it is Clear C protists
Answer:
A. Average plant height increases with an increase in the concentration of sodium phosphate until the plants reach a maximum possible height.
Explanation:
The graph in the attachment section portrays the average height of plants (cm) on the y-axis plotted against the concentration of sodium phoshate (mg/L) on the x-axis. Based on the observation of the result in the graph, an increase in the concentration of phosphate caused an increase in the average plant height (as depicted by the upward-sloping line).
However, the plant's average height didn't go beyond 35cm despite an increase in concentration of phosphate. This is because the plants has reached a maximum possible height i.e. a height climax. Hence, they cannot grow taller than 35cm no matter the amount of external nutrients (sodium phosphate) supplied.
Therefore, the noticeable trend that can be used to make a conclusion is that average plant height increases with an increase in the concentration of sodium phosphate until the plants reach a maximum possible height.
Answer:
B.) They have the same color and texture.
