<span>The current estimated total number of species on earth is between five million and hundred million.
The reason why it is hard to get an accurate count is because some species are very hard to find reason being that of nocturnal habits, location, and the size.
All the species which have ever lived on earth are being estimated to be extinct. It is approximately one extinction for every million species for years. Mammals species like typically persist for one million years.</span>
lysosomes contain digestive enzymes which help break down excess or worn-out cell parts
Plant cells have a cell wall that is very rigid, which forces the cell to shape that way. Animal cells are round because they don’t have a cell wall only a plasma membrane
C. Oxygen and nutrients taken in by the respiratory system are transported to the circulatory system for transport around the entire body.
Also, B and D cannot be correct, as carbon dioxide is not wanted in the body (it's a waste product of respiration of the body cells)
