What causes the cells to be identical?

What causes the cells to be identical?

Most of the time when people refer to “cell division,” they mean mitosis, the process of making new body cells. Meiosis is the type of cell division that creates egg and sperm cells. During mitosis, a cell duplicates all of its contents, including its chromosomes, and splits to form two identical daughter cells.

Why are mitosis cells genetically identical?

Mitosis creates two identical daughter cells that each contain the same number of chromosomes as their parent cell. These new combinations result from the exchange of DNA between paired chromosomes. Such exchange means that the gametes produced through meiosis exhibit an amazing range of genetic variation.

What happens during prophase stage?

During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses. The chromatin coils and becomes increasingly compact, resulting in the formation of visible chromosomes. Chromosomes are made of a single piece of DNA that is highly organized.

What shape do the replicated cells look like in prophase of the original cell?

Prophase, metaphase, anaphase, and telophase. 5. What shape do the replicated chromosomes look like in prophase of the original cell? They look like X’s.

What does a cell look like during prophase?

During prophase, the molecules of DNA condense, becoming shorter and thicker until they take on the traditional X-shaped appearance. The nuclear envelope breaks down, and the nucleolus disappears. When you look at a cell in prophase under the microscope, you will see thick strands of DNA loose in the cell.

Why does prophase take the longest?

The longest phase of mitosis is prophase because During prophase, which occurs after G2 interphase, the cell prepares to divide by tightly condensing its chromosomes and initiates mitotic spindle formation. The chromatin fibers condenses into discrete chromosomes. The nucleolus also disappears during early prophase.

How many replicated chromosomes are in the original cell shown during prophase?

The genetic material of the cell is duplicated during S phase of interphase just as it was with mitosis resulting in 46 chromosomes and 92 chromatids during Prophase I and Metaphase I.

What does each duplicated chromosome have two of?

each DUPLICATED chromosome has two sister chromatids. The two chromatids each contin an identical DNA molecule and are attached by cohesins which is a protein complex. – also known as sister chromatid cohesion. Before duplication each chromosome has a single DNA molecule.

Why are there two stages of prophase in mitosis?

During prophase of mitosis, the molecular motors and necessary condensation of the DNA allows the sister chromatids to be separated. There are two stages of prophase during meiosis. Meiosis consists of two separate cell divisions, separated by a phase known as interkinesis.

What do chromosomes look like in prophase I?

At this first stage of Prophase I of meiosis I chromosomes are visible under electron microscopy and look like ‘a string of beads’, where the beads are referred to as nucleosomes. If fully stretched out, some DNA may be nearly a centimeter long – much too large for a cell nucleolus.

What happens to the centrosome during prophase II?

Though the DNA exists as duplicate sister chromatids, only one half of each homologous pair is present in each cell. As in prophase of mitosis, the centrosome containing microtubules separates to each side of each cell during prophase II.

What happens to spindle microtubules during prophase?

Prophase is followed by prometaphase, which is a subphase of metaphase. During prometaphase, the nuclear membrane is broken down, allowing the spindle microtubules to invade the nucleus. Spindle microtubules are attached to the kinetochore protein complexes in the centromeres of the chromosomes.