When puppies ears start standing up is it sudden or gradual?

What is the main difference between the central nervous system (cns) and the peripheral nervous system (pns)? .the cns involves the brain and spinal cord, and the pns involves the body nerves. the cns involves the body nerves, and the pns involves the brain and spinal cord. the cns involves sensory neurons, and the pns involves motor neurons. the cns involves motor neurons, and the pns involves sensory neurons.

What is genetic variation? -(a) each individual in a population has slightly different genes. -(b) some individuals in a population have more genes than others. -(c) each population of a species has slightly different genes. -(d)some populations of a species have more genes than others.

Scientists discovered fossils in several layers of the earth you see here. they found fossils of algae, snails, and clams in layer d. given that information, where do you think they found fossil evidence of simple land plants and amphibians? a. a b. e c. f d. g