Where does rna polymerase begin transcribing a gene into mrna? see concept 17.2 ( page 342)?

RNA polymerase starts the transcription of a gene into mRNA by binding to a specific DNA sequence region called a promoter. RNA polymerase moves past the promoter until it reaches the start sequence of the gene to be transcribed in a 5 to 3 direction.

That is true tge cactus as a structural adaptation to its envirinment has it leaves reduced to spines. but this doesnt mean it cant produce food it produces food because of the presence of chlorophyll in its stem