Describe the research work of Melvin Calvin regarding photosynthesis.

(N/A) Melvin Calvin,an American biochemist,conducted pioneering research on the path of carbon in photosynthesis using the radioactive isotope $C^{14}$.
$1$. He used the unicellular green alga $Chlorella$ and $Scenedesmus$ for his experiments.
$2$. He employed the technique of paper chromatography and autoradiography to trace the movement of carbon.
$3$. He discovered that the first stable product formed after $CO_2$ fixation in the dark reaction is a $3$-carbon compound called $3$-phosphoglyceric acid ($3$-$PGA$).
$4$. This discovery led to the identification of the $C_3$ cycle,which is now famously known as the Calvin Cycle.
$5$. For his significant contribution to understanding the mechanism of photosynthesis,he was awarded the Nobel Prize in Chemistry in $1961$.