Cuticle is to prevent water loss and the stomata placing in the bottom can reduce the evaporation of water because if it's place on top the sun will evaporate the water inside
1. Testing only one variable
A controlled variable means its the one that stays the same. In a controlled experiment, it means there is only one manipulated, (changed) variable.
Answer: elastic fibers
Explanation:
Elastic fibres are the essential durable component present in mammalian connective tissueand functions to provide proper pulmonary, cardiovascular and intestinal system structure and function. Their structural function is to provide elastic recoil and resilience for the tissues.
Elastin fibers ahve two main including microfibrils and elastin containing fibrillin play a mechanical and structural role in the arteries, and their important function is to provide the tissues with resilience and elasticity.
Hence, elastic fibers helps arteries to adapt to changes in blood pressures that accompany the heartbeat.
Because you might have just done something different with the experiment and messed up someway during the test