1. Iron is required for the formation of hemoglobin.

2. Hemoglobin is a part of red blood cells that carries oxygen and removes carbon dioxide (a waste product) from the body.

3. Iron is stored in the body mainly in hemoglobin.

Actually, the locomotor part of a hydra is not its tentacles. Hydras move by a remarkable way called "looping." They attach one end of their body to a surface and then release the other end, allowing it to move and attach again. This looping movement is facilitated by the contraction and expansion of the body, rather than the use of tentacles. Tentacles are specialized structures primarily used for feeding and defense in hydras.

1 volt = 1 joule / 1 coulomb

This equation represents the definition of voltage (in volts). It states that one volt is equal to one joule of energy per one coulomb of charge. Voltage measures the electric potential difference between two points and is a fundamental concept in electrical physics.