The part of the plant where gas exchange does not take place isLeafFlowerRootStem

The part of the plant where gas exchange does not take place is the Flower.

Here's why:

1. Leaf: The leaf is the primary site of photosynthesis in plants, which is a process that converts carbon dioxide and sunlight into oxygen and glucose. This process involves gas exchange, so it does occur in the leaf.

2. Flower: The flower is primarily involved in reproduction. It does not have stomata - the tiny openings found in the leaf and stem that allow for gas exchange. Therefore, gas exchange does not occur in the flower.

3. Root: The root also has a role in gas exchange. Oxygen from the air spaces in the soil diffuses into the root hairs and then into the root cells where it is used in respiration. Carbon dioxide, a waste product of respiration, diffuses out of the root in the same way.

4. Stem: The stem, like the leaf, has stomata which allow for gas exchange to support processes like photosynthesis and respiration.

So, the flower is the part of the plant where gas exchange does not take place.