12) How do harvesting wood and surface mining for coal affect ecosystems?

no

Explanation:

because mining coal is not gonna affect eco system and coal mining is not good foy your body

i think it is dna, i'm not totally sure but i think it might be.

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.