Explain how seasonal fires benefit grassland ecosystems

Fire is a natural part of the grassland ecosystem and helps maintain its health and vigor. It warms up the soil and reduces the leaf litter that accumulates each year, allowing sunlight to penetrate. ... After a fire, blackened fields quickly revive with new, green grasses and abundant, showy wildflowers.

some inherited genetic mutations can be good for the offspring, so the answer is different genetic mutations cause many forms of cancer.