And It's Getting Deeper. At the Grand Canyons deepest point, it is over a mile (1.83 kilometers) from its top to its floor. A landform is a feature on the Earth's surface that is part of the terrain. Mountains, hills, plateaus, and plains are the four major types of landforms. Minor landforms include buttes, canyons, valleys, and basins. Tectonic plate movement under the Earth can create landforms by pushing up mountains and hills.
The cell cycle. Actively dividing eukaryote cells pass through a series of stages known collectively as the cell cycle: two gap phases (G1 and G2); an S (for synthesis) phase, in which the genetic material is duplicated; and an M phase, in which mitosis partitions the genetic material and the cell divides. 1  G1 phase. Metabolic changes prepare the cell for division. 2  At a certain point-the restriction point-the cell is committed to division and moves into the S phase. 3  S phase. 4  DNA synthesis replicates the genetic material.
The mitotic phase which includes both mitosis and cytokinesis is the shortest part of the cell cycle. The interphase cycle accounts for about 90% of the cell cycle. This phase is where the cell grows and copies its chromosomes in preparation for cell division. In the G1 phase which is also called the âfirst gapâ the cell grows as it copies its chromosomes. In S phase, the cell starts to synthesize the DNA and completes preparation for cell division. In G2 it starts to divide.