<u>Answer:</u>
<em>A constant is something whose value cannot be changed and is used for comparison purpose. </em>
<u>Explanation:</u>
The controlled variable is a type of variable whose value is kept constant during the experiment to get the desired or expected result. The difference between constant and a control variable is that the constant can never be changed.
However, the value of control variable can be changed but is kept constant with a purpose in an experiment to get the data. The controlled variable in a battery can be the multi meter that should be used for all the batteries.
Plants do not breathe, they only respire. No such respiratory organ os present in plants. The carbon dioxide produced in animals during respiration is released to the atmosphere, whereas the carbondioxide produced during plant respiration may be used by the plant for carrying out photosynthesis.
Answer: it is b
Explanation:I DID THIS TEST
we need a graph to do this can u provide a picture?