How is corona virus mutated as it spreads?

As the new coronavirus continues to spread around the globe, researchers say the virus is changing its genetic makeup slightly. But does that mean it is becoming more dangerous to humans? And what would the impact be on any future vaccines?

answer; the male's sperm cells have mitochondria, but because the sperm contributes dna but no cytoplasm, no mitochondria are passed to the egg at ferilization;