How many other passive transport across the cell membrane are similar to diffusion ?

yes it would be pssible

scientific consensus is : a general agreement among scientists about a scientific idea.

even though consensus implied general agreement, it doesn't mean unanimity. for example, scientists generally agree that meteor caused dinosaur's extinction. though this may not be proven yet, but it considered a consensus.

hope it

the calvin cycle takes place in the stroma of the chloroplast. carbon dioxide enters the stroma of the chloroplast to combine with the five-carbon compound called ribulose1, 5-biphosphate to form two molecules of a three-carbon compound called 3-phosphoglyceric acid. this reaction is catalyzed by an enzyme called ribulose bi-phosphate carboxylase.