When the knee is hit with a rubber hammer, the leg kicks forward, and then returns to the original position. this is an example of a spinal reflex arc. the sensation of the hammer travels to the , where it activates motor neurons that cause the leg to move. this reflex is part of nervous system

1. The right answer is Spinal cord (central nervous system).

The spinal cord is a long and fragile tubular structure that begins at the lower end of the brainstem and ends at the bottom of the spine (spine). The spinal cord is made up of nerve fibers that carry incoming and outgoing messages that circulate between the brain and the rest of the body. It is also the center of reflexes, like the patellar reflex.

2. The right answer is Vegetative nervous system (called also autonomic nervous system).

The autonomic nervous system or visceral nervous system (also called the vegetative nervous system) is the part of the nervous system responsible for functions not subject to voluntary control. It controls particularly smooth muscles (digestion, vascularization ...), heart muscles, the majority of exocrine glands (digestion, sweating ...) and certain endocrine glands. The autonomic nervous system contains peripheral but also central neurons.

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation:

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