Which parts of a nervous reflex arc is usually a muscle or gland?

The given question is incomplete as it does not have the options which are:

a) Sensory receptor

b) Sensory neuron

c) Motor neuron

d) Effector

e) Integration center

The correct answer is option-Effector

Explanation:

A reflex arc is the mechanism of the neurons which controls the reflex action or involuntary responses or the instantaneous responses of the organisms.

The reflex arc involves the sensory receptors, sensory neurons (transmit signals from sense organ to spinal cord), motor neurons (transmit signals from spinal cord to muscle), Integration centre in the spinal cord and effector.

An effector represents the gland or the muscle which receives the transmitted signal from the motor neuron and responds by showing movements.

Thus, option-Effector is the correct answer.

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg 

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?