I believe the example of an environmental variation in the above question is, A. Marge dyes her hair blue. Variation represents any difference between cells, individual organisms, or groups of organisms of any species caused by either genetic differences or by the effect of environmental factors. Environmental variation is the ability of an organism to alter its phenotype depending on environmental conditions.
Hello! The best answer would be C - Colds because bacteria can reproduce and spread rapidly, which is why a cold sometimes develops fast. As for the others, your body is just adjusting to the weather with A, B is a sexually transmitted disease which is caused from contact with another through sex, D is caused by sweets/certain foods that break down your teeth. I hope I helped you!! Have a great day!!
Water is in the hydrosphere
Hope this helps
A) Crossing over is the mechanism of genetic variation that results from the exchange of gene segments between non-sister chomatids.