If less is the only option then go with that like your question suggests but more feels like a better answer
Answer: The taproot
Explanation: A deep taproot helps plants use moisture held in deeper soil layers, and they can have great drought resistance compared to fibrous-rooted plants. An example is honey mesquite (Prosopis juliflora), which is known to send its roots down 150 feet to get water.
Answer:
red blood cells or formed in the red bone marrow of bones
Photosynthesis contributes to plant growth by B. taking in carbon dioxide and making sugars (carbohydrates)