Answer:
As they produce food by the process of photosynthesis which cannot be done by anyone else. Plants use chlorophyll, CO2 and H2O in photosynthesis( which is a biochemical process). Plants became a cause of life on earth. Hence plants are the ultimate source of food on earth.
Molecular clocks use rates of mutation to measure evolutionary time.Mutations add up at a fairly constant rate in the DNA of species that evolved from a common ancestor. The more mutations that happened in each lineage, the greater is the differences between these lineages.
Answer:
there are all kinds of signals occur in the brain
Explanation:
Hope this help not sure if it is the right answer
Smoking ruins your lungs making it harder to breath and get oxygen
you need oxygen when you exercise so you don't faint
smokers get less so it is harder for them, its like trying to exercise while breathing through a sponge or a straw os