The small intestines give nutrients to the blood
There are some organelles which are found in plant cells but which are not found in the animal cells, these structures will provide a positive identification of a plant cell under a microscope.
The structures which would provide a positive identification of a plant cell under a microscope are CENTRAL VACUOLE, CHLOROPLAST [PLASTIDS] AND CELL WALL. These structures are only present in plant cells.
B or d.... hope this helps:)
Answer:
1.) stromatolites
2.) photosynthesis
3.) Ordovician
4.) Cambrian
5.) oxygen
6.) As Earth cooled, carbon dioxide dissolved in the early ocean. Cyanobacteria consumed carbon dioxide and converted it to oxygen. Methane was removed from the atmosphere as oxygen was produced, eventually leading to the Cambrian Explosion.
7.) Metabolic processes that use oxygen produce more energy than anaerobic metabolism. Simple diffusion of oxygen would limit the size of a multicellular eukaryote, but animals evolved ways to transport oxygen to their tissues, which permitted an increase in size.
Explanation:
From Penn
Organelles must do their duties together and their activities must be coordinated I'm pretty sure.