Explanation: Cytokinesis is the physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells. It occurs concurrently with two types of nuclear division called mitosis and meiosis, which occur in animal cells. Mitosis and each of the two meiotic divisions result in two separate nuclei contained within a single cell. Cytokinesis performs an essential process to separate the cell in half and ensure that one nucleus ends up in each daughter cell. Cytokinesis starts during the nuclear division phase called anaphase and continues through telophase. A ring of protein filaments called the contractile ring forms around the equator of the cell just beneath the plasma membrane. The contractile ring shrinks at the equator of the cell, pinching the plasma membrane inward, and forming what is called a cleavage furrow. Eventually, the contractile ring shrinks to the point that there are two separate cells each bound by its own plasma membrane.
The answer is D. in animal cells, the cell membrane allows materials in and out of the cell, while the mitochondria uses nutrients to make energy (ATP) for the cell.
Continental crust is typically 40 km (25 miles) thick, while oceanic crust is much thinner, averaging about 6 km (4 miles) in thickness. The effect of the different densities of lithospheric rock can be seen in the different average elevations of continental and oceanic crust.
