Question

What happens in the prophase of mitosis?

Answer 1

Mitosis in cell biology, is part of the cell cycle in which the duplicated chromosomes separate into two new cell nuclei. Cell division produces genetically identical cells in which the total number of chromosomes is maintained. Therefore, mitosis is also called equational division. Generally speaking, mitosis (nucleus division) is preceded by the S phase of the interphase (during DNA replication), and is usually followed by telophase and cytokinesis.

Complete answer:
Mitosis is the first stage of mitosis, the process of splitting the duplicated genetic material carried in the nucleus of the parent cell into two identical daughter cells. During prophase, complexes of DNA and proteins in the nucleus, called chromatin, condense. The chromatin coils up and becomes tighter and tighter, leading to the formation of visible chromosomes.
Chromosomes are made up of a highly organized segment of DNA. The duplicated chromosomes have an X shape and are called sister chromatids. Sister chromatids are pairs of identical copies of DNA joined together at a point called the centromere. After that, a structure called mitotic spindle begins to form. Mitotic spindles are made up of long proteins called microtubules that begin to form at opposite ends of the cell. These spindles are responsible for the separation of sister chromatids into two cells. Prophase, which is the first stage, is followed by the second stage of mitosis, known as the prometaphase phase.

Note:
Mitosis only occurs in eukaryotic cells. Prokaryotic cells, devoid of a nucleus, divide by another process called binary fission. Mitosis varies among organisms. For example, animal cells undergo "open" mitosis, where the nuclear envelope is broken down before the chromosomes separate, while fungi undergo "closed" mitosis, where the chromosomes divide in an intact cell nucleus.