This is more of a personal question about how well you know yourself, no one can answer this for you.
Answer: 4
Explanation:
It is composed of a cell, but does not have
tissues.
As of 2014, it was often reported in popular media and in the scientific literature that there are about 10<span> times as many microbial cells in the human body than there are human cells; this figure was based on estimates that the human microbiome includes around </span>100 trillion<span> bacterial cells and an adult human</span>
The answer is photosynthesis.
<span>Photosynthesis
occurs in the leaves of green plants. During photosynthesis, carbon
dioxide and water are converted into using the energy of
sunlight to glucose and oxygen. After great evolution of plants, the photosynthetic rate was increased. More plants mean more oxygen produced in the process of photosynthesis. Thus, photosynthesis </span><span> is most responsible for the increase in early Earth’s atmospheric oxygen levels.</span>
