<span>It is well known that the centrosome acts as a microtubule organizing center, with its textbook role in forming mitotic spindles in dividing cells. So in many cells, the centrosome with its centrioles is indeed essential to ensure correct cell division, and in these the PCM ensures the distribution of the right number of centrioles to each daughter cell. But there are exceptions – which include somatic cells in fruit flies and some fungi – where no centrioles are needed; and centrosomes in some differentiated cells, including neurons and muscle cells, are inactive.</span>
It is the muscle that is most used in boxing of course!
Hope this helped!
It would be B. Photosynthesis
The system you're looking for should be "digestive system".
This organ system consists of organs such as mouth, stomach, intestines etc.
Basically, how this system works is that it breaks down complex and insoluble food molecules by using enzymes (chemical digestion) , into simple and soluble molecules which can be absorbed by the body and be turned to energy for our body to work. Examples of chemical digestion is such as enzyme lipase digesting lipids into fatty acids and glycerol. In addition, physical digestion (without enzymes) is also used to help speed up chemical digestions. Examples of physical digestion is where we chew the food we eat into a bolus, which can increase the surface area of the food and the enzyme digestion later on can be faster and more efficient.