Reflexes may be coordinated by the brain or by the spinal cord. in reflexes co-ordinated by the brain, there are no relay neurones. suggest why there is a difference in the mean speed of the impulse for the two reflexes.

What is the best conclusion based on this data? the hypothesis was not supported because the data indicated that fertilizing plants does not improve plant growth. the hypothesis was supported; to get the best growth, use 5 milliliters of fertilizer per plant. the hypothesis was not supported; the data indicated that too much fertilizer can inhibit plant growth. the hypothesis was supported; to get the best growth, use 15 milliliters of fertilizer per plant.

In general, characteristics that an organism survive and reproduce become more common in a population over time. what mechanism of evolution cause this change?

Body temperature is tightly regulated in mammals for example when external temperatures drop too much the body of a mammal response by in order to it's core temperature.