Why do many reflexes, such as pulling your hand away from a hot iron, happen so quickly?

These reflexes involve relatively few neurons so that they can occur  rapidly because the message which neuron carry does not need to go all the way to the brain.

Explanation:

Reflexes are responses which quickly occur to protect our body from potentially harmful condition like touching the hot iron. A reflex is a rapid,automatic and unlearned response to a  stimulus. These reflexes involve relatively few neurons so that they can occur  rapidly because the message which neuron carry does not need to go all the way to the brain.

A reflex occurs when nerve impulses travel through a path which is known as reflex arc. There are five parts in reflex arcs . These are receptors, sensory neurons, inter neurons, motor neurons and effectors.

When we touch something that is very hot, our hand moves away quickly before even we feel  the pain. During this reflex action we don’t have to think about it because this reflex does not involve the brain.

sand 60

clay 10

silt 30

sandy loam should be dominated by the sand. as the amount of sand increased, the amount of slit needed to anchor the plants' roots to the sand will also be increased. even though the amount is very little, 10% part of clay is still necessary for proper oxidation.

the median of the data is 4.5.