Answer:
Pollen
Explanation:
Pollen is a powdery substance consisting of pollen grains which are male microgametophytes of seed plants, which produce male gametes (sperm cells).
The answer is C. They lower the activation energy of an elementary step of a reaction
This makes the reaction rate to increase since less energy is required to make a reaction occur.
Making an atom or a virus structure
Claim: Earth's atmospheric CO2 levels were measured over the past 1000 years and correlated with average world temperatures. The data demostrate that Earth's temperature did not change during the period CO2 levels were steady. But the past 100 years show a dramatic rise in CO2 levels, with a corresponding rise in world temperatures. The CO2 rise can be traced back to the start of the industrial revolution, when machines began doing much of the work. These machine burn fossil fuels and the increased CO2 levels have led to a dramatic rise in world temperatures. The data clearly show the importance of reducing fossil fuel useage, as well as other CO2 emitters. A world of incresing temperatures will lead to greater natural disasters, such as storms, flooding, hurricanes, and drought - all of which upset the ecological balance of the planet.
