I think is the first and second!!
Both flagella and pili are extensions from the bacterial cell body. Flagella are like a whip or a tail while pili are best described as hairlike.A pilus is a hairlike appendage found on the surface of many bacteria.
A plasma membrane Hope it helped.
Sensory receptor
Sensory receptor is known to
be a structure that responds to a physical stimulus in the environment which
can either be external or internal. Also, sensory receptor generally initiates the
same process of creating nerve signals and registering stimuli. Generally, sensory receptor usually serves as the front liner because they are in contact
with the stimulus.
