D. homologous chromosomes pair up
It would affect our environment very badly. The following reasons are why it is bad: 1)Trees are our main supply of oxygen. 2) Corn is slow at converting carbon dioxide into oxygen. 3) Many wildlife creatures (plants and animals) need that ecosystem to live.
The tilt of the earth's axis, which essentially "turns" certain parts of earth so that some parts receive more direct sunlight
The answer in the space provided is anaerobic respiration.
It is because this allows of having to utilize other substance than oxygen such
as nitrate or sulfate to be their electron acceptors in which is for organisms
that undergoes respiration.