$A$ doctor advised a person to take an injection of insulin because

What happens at the synapse between two neurons?

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

The response of plants to stimuli is limited because $...$

Which of the following statements are true?
$(i)$ Sudden action in response to something in the environment is called reflex action.
$(ii)$ Sensory neurons carry signals from spinal cord to muscles.
$(iii)$ Motor neurons carry signals from receptors to spinal cord.
$(iv)$ The path through which signals are transmitted from a receptor to a muscle or a gland is called reflex arc.

Dwarfism results due to :