Answer:
Humans impact the physical environment in many ways: overpopulation, pollution, burning fossil fuels, and deforestation. Changes like these have triggered climate change, soil erosion, poor air quality, and undrinkable water.
Cell maintain homeostasis through diffusion in isotonic solution. Isotonic means that the concentrations are the same on either side of the membrane, maintaining homeostasis.
Exactly how many chromosomes we are talking about depends on the species. A mosquito has 6 chromosomes, a pea plant has 14, a sunflower 34, a human being 46, and a dog 78. Closely related species tend to have a similar number of chromosomes.