Ask AI: What are some of the observable features for mitosis of animal sec.

Mitosis is a process of cell division in eukaryotic cells. It is easy to observe under a microscope, particularly in animal cells, and has a number of key, identifiable features: 1. **Interphase:** The cell is in its normal state before mitosis begins. In this phase, the DNA in the form of chromatin is not visible and the nucleus appear normal. The cell gets ready for the next phase by duplicating its DNA and its centrosomes (the spots where the microtubules attach and which help in pulling the chromosomes apart in the next stages). 2. **Prophase:** The chromatin starts to coil up and condense into distinct chromosomes, which are duplicated and joined at the middle (called the centromere). The two duplicated chromosomes are called sister chromatids. The nucleoli begin to disappear, and the mitotic spindle (composed of microtubules) starts to form from the centrosomes, which move towards the opposite ends, or 'poles', of the cell. 3. **Metaphase:** The chromosomes line up along the metaphase plate (an imaginary line across the middle of the cell). Here, the centromeres attach to the spindle fibers. 4. **Anaphase:** The centromeres divide, and the sister chromatids are pulled apart by the shortening of the spindle fibers. The chromatids, now separate chromosomes, move to the opposite poles of the cell. 5. **Telophase:** New nuclear envelopes form around each set of chromosomes, and the chromosomes start to decondense back into chromatin. The spindle fibers also disappear. This phase often overlaps with cytokinesis. 6. **Cytokinesis:** This is not technically part of mitosis, but it's often included under the umbrella because it's the process by which the cell finally splits into two distinct daughter cells. In animal cells, this is achieved through a process called cleavage, where the cell pinches in at the center until it divides. Remember, while you can see these stages under a microscope, if the cell isn't stained properly or the light levels aren't adjusted correctly, it can be difficult to see the chromosomes and spindle fibers. Additionally, cells do not all go through mitosis at the same time, so not all cells in a field of view will necessarily be at the same stage.