Answer:
Ascending tracts
Explanation:
The spinal cord consists of ascending and descending tracts. The ascending tracts are sensory pathways that travel through the white matter of the spinal cord, carrying somatosensory information up to the brain.
Answer:
Mass extinctions, like the one that killed the non-bird dinosaurs, leave behind a host of empty niches — unoccupied ecological real estate. The upshot of all these processes is that mass extinctions tend to be followed by periods of rapid diversification and adaptive radiation.
Explanation: