Because the oxygen produced in photosynthesis is used in respiration, and the carbon dioxide produced in respiration is used in photosynthesis.
The answer is stem cells. Normal stem cells and germ cells can also be said to be immortal
It is probably the l<span>amellae.
The lamellae are sheets of bony matrix. This bony matrix is produced by o</span>steoblasts, which are cells that synthesise collagen<span> and specialised proteins like </span>osteocalcin<span> and </span>osteopontin. These are then the most important constituents of the bony matrix.
The DNA is splitting in two, thymine pairs with adenine, and guanine pairs with cytosine