If a potted plant is kept horizontally for a few days,in which direction does the tender stem of the plant grow?

Which hormone from the pituitary gland stimulates the reabsorption of water and regulates water loss through urine?

State in brief how the communication between the central nervous system and the other parts of the body is facilitated.

$(a)$ Name one organ each where growth hormone is synthesized in man and plant.
$(b)$ List the sequence of events that occur when a plant is exposed to unidirectional light,leading to bending of a growing shoot. Also,name the hormone and the type of movement.

Iodine is necessary for the synthesis of which hormone?

What is a synapse?