Answer:
A. One cell took over another cell
Explanation:
Mitochondria is an organelle present in a eukaryotic cell that performs the function of producing ATP molecules from the available substrates in the cell.
The mitochondria organelle has its DNA other than the cellular DNA which shows that it was once an independent organism. This was proved by the endosymbiotic theory that during the formation of the eukaryote cell, the proto-eukaryote engulfed the chemosynthetic bacteria which later formed the symbiotic relationship with the cell and evolved into the mitochondria.
Thus, Option-A is the correct answer.
A disaccharide is a sugar formed by 2 monosaccharides, 2 examples are sucrose and lactose
Answer:
b. Cellular clock is the correct answer.
Explanation:
Cellular clock theory states that cells can divide a maximum of about 75 to 80 times, and that as we age our cells become less capable of dividing.
Cellular clock theory directs on the lifespan of organisms. As the many individual cells do not remain to reproduce continually, so this theory implies that aging of the cells is a result of their reproductive limitation and because of cellular aging.
Cellular clock theory is the theory Leonard Hayflick's that describes the cellular aging mechanism and it suggests that as the cell becomes aged it becomes less effective of dividing.