Animals use the respiratory system to breathe in oxygen and other gases and expel gases like CO2, right? O2 in, CO2 out.
The answer is A. Environmental conditions are not always right to produce flowers and seeds for sexual reproduction.
Most plants are able to reproduce either way because even if the conditions aren't right for the plant, it can still make more flowers so it doesn't die out.
I hope this helps! :D
<span>Deforestation affects biogeochemical cycling mainly by disrupting the water cycle, causing water to be lost more rapidly from the ecosystem and with it important elements and nutrients. this was from socratic.com, it isnt my words but its an answer </span>