Hi,
I think that you're missing some options, but here they are (let me know if I'm right!
-A population of wolves was introduced
-The amount of disease in the deer population decreased
-More grass was planted
Now, if the gene diversity decreased, it means that a lot of deer died. This could happen because wolves were introduced -this is the correct answer, and the wolves ate some deer.
Because the hemoglbin genes have been split into amino acids
The brain is incorrect. Its the nucleus (the brain is an organ not a organelle)
hope that helps :)
