The smallest living unit is actually a cell. An organelle is an organ inside of a cell. An organelle would not be considered alive because it can not survive without the other organelles. Whereas, a cell can survive without other cells.
I think that since they actually attach to cells inside the body, they don't count as cells. They're capable of getting in cells, but viruses themselves are actually made up of nucleic acid.
The best and most correct answer among the choices provided by the question is the second choice. Our immune system has certain defense mechanics that protects us from pathogens, such examples are the white blood cells. <span>I hope my answer has come to your help. God bless and have a nice day ahead!</span>
Answer:
Four
Explanation:
Like all proteins, the "blueprint" for hemoglobin exists in DNA.
