I believe plant cells because the only cells that have walls are plant cells and cellulose is strong and will help remain its shape.
<span>humus; Increase..................................................</span>
Life would not exist. The ozone layer is keeping all the gasses from escaping into space. So, without the ozone layer, there would be no oxygen for animals or carbon dioxide for plants. The ozone layer also reflects space radiation and harmful UV rays back into space, preventing them getting into the Earth's atmosphere.
It is an indicator of poor air quality from air pollution. This pollution is most often ozone or particulates. Typically it indicates that the air is unhealthy for children, the elderly, and sensitive groups.
