The central nervous system is the center of the body like a spinal chord in stuff peripheral nervous system is the sides like your arm's, Legs anything that's outside the spinal chord area
Answer:
i believe the answer is bilateral symmetry
INVERTEBRATE refers to animals such as insects, sea anemones, and worms that lack an interior skeleton.
Interior skeleton are also identified as back bone. So organisms without back bone are called invertebrates.
A confounding variable refers to an external effect, which modifies the influence of an independent and dependent variable. This extraneous effect is used to affect the outcome of an experimental design. The confounding variables can ruin the experiment and can generate unnecessary outcomes.
In the given case, confounding variables can be introduced by testing multiple hypotheses at a time and by using distinct kinds of soil in each of the samples.