Answer:
B. Early Eukaryotic cells engulfed mitochondria and chloroplasts
Explanation:
Mitochondria and Chloroplast are organelle that are found in cells of higher animals. Chloroplast are found almost exclusively in plants and mitochondria is found in animal cells. The function of these organelles are to produce energy to the cells, and by extension, the organism that they live in.
Unique features of these organelles show that they have their own DNA and divide and multiply on their own. This strongly suggest that they were once free living prokaryotes and were engulfed by larger cells and a symbiotic relationship began.
As time progressed, these prokaryotes did not require all of their genetic information and this was removed from their system. They kept essential genes and regulatory bodies separate that they needed for their maintenance and function that they provide.
When a stem cell divides, each new cell can either stay a stem cell or become a specialized cell, such as a muscle cell, a red blood cell, or a brain cell.
Answer:
The amount of energy at each trophic level decreases as it moves through an ecosystem. As little as 10 percent of the energy at any trophic level is transferred to the next level; the rest is lost largely through metabolic processes as heat
oxygen can only hold two bonds with other elements.