The three stages of the cell cycle are interphase, mitosis and cytokinesis. The DNA replication occurs in interphase, followed by the division of the DNA strands in mitosis and replication and division of nucleus, and other cell parts during cytokinesis.

The three stages of the cell cycle are interphase, mitosis and cytokinesis.

Replication of DNA occurs during the first phase; the interphase of cell division.

The process of mitosis is further divided in 4 stages:

1. The prophase is the first stage in mitosis during which the DNA strands or the chromosomes condense and become compact. Each chromosome is made up of 2 identical strands to be transferred to the daughter cells on division.

2. Metaphase is the second stage in mitosis during which the chromosome line up for cell division to occur.

3. Anaphase is the third stage in mitosis during which the DNA strands become divided. They travel to opposite ends of the parent cell after separation.

4. Tellophase is the forth stage of mitosis during which the chromosome strands stretch out. Two nuclei seem to be formed in the same parent cell, one of each of the 2 daughter cells to be produced.

a. Figure i and ii show a plant cell while Figure iii and iv show an animal cell. The cell wall of the plant cell indicates it to be a plant cell.

b. Figure i and iii show the stage of mitosis and more specifically, the metaphase during mitosis. This is indicated by the lined up chromosomes.

b. Figure ii and iv show the stage of mitosis and more specifically, the telophase during mitosis. This is indicated by the two nuclei in the same parent cell. These nuclei will each go to each one of the two resulting daughter cells.

The uncontrollable growth mechanism of cancer cells make them dangerous. Uncontrollable growth means that they will grow out of proportion to create lumps in the body, extracting nutrients from the surrounding cells and rendering them dead as they do so.

The process of diffusion is responsible for spreading of the odor from one place to another.

The process of cell division is identical in plant and animal cell for the first two stages. The difference occur in the cytokinesis stage where in plant cell a plate develops between the two separated nuclei. This plate stretches to separate the cell in to two parts and later becomes the cell wall of the adjacent daughter cells. In animal cell, no such structure is formed and the cell membrane gathers around the new nuclei finally dividing the parent cell into daughter cells.

Mitosis is important for multi-cellular organisms to ensure the growth and sustainability of the organism. The process of mitosis ensures that the resulting daughter cells are exact replicas of their parent cells.

Normal cells undergo the interphase during which the DNA of the parent cell is replicated to make two daughter cells. This stage takes an elaborated amount of time to ensure that the replication of the DNA is accurate. This does not happen in a cancer cell. Cancer cells undergo short interphases during which the DNA fails to replicate as a result of which the DNA is not only copied in correctly but its ability to control growth is lost leading to uncontrollable growth of all the parent and daughter cells to form useless masses of lumps in the body.

The centromere holding the two identical strands of DNA/chromosome is responsible for the movement of chromosomes during mitosis. During the anaphase, this centromere releases the two strands separating them to two sister chromatids. These chromatids move to opposite ends of the cell.

Two strands of chromatids when held together by the centromere is called a chromosome.

a. Cells have to maintain their relatively small size so that they can efficiently participate in diffusion. We know that the cells gain their nutrients from their surroundings and excrete their wastes out by the process of diffusion. The faster the rate of this diffusion, the more efficient the cell is. According to surface area to volume ratio theory, the smaller a cell, the larger is its surface area to volume ratio and therefore the more efficiently it can allow diffusion to occur via its body.

b. As written in a, according to surface area to volume ratio theory, the smaller a cell, the larger is its surface area to
volume ratio and therefore the more efficiently it can allow diffusion to occur via its body. Muscles cells are required to be active and therefore need to be smaller in size so that they can fulfill their role in the human body. Fats cells only purpose is to store excess nutrients of the body as fats, they do not actively participate in bodily functions and therefore afford to be slightly larger in size.

Skin is the first defensive mechanism of an organism’s body. It is the most exposed part of an organism and therefore prone to be the first to get attacked by the harmful radiations of X-rays and ultraviolet from the sun as well as tanning places.

Depending on the specie of the plant, roots, branches and leaves undergo frequent mitosis for the plant to grow larger in size and stronger in health.

Eating healthy, avoiding exposure to tobacco smoke (both active and passive), exercising regularly and self-examining your body can help an individual stay fit and prevent him/her from falling as a prey to this deadly disease.

text a) \
text The total number of counted cells in sample A is :337 \
The total number of counted cells in sample B is :326 \ \

setlength{tabcolsep}{18pt}
renewcommand{arraystretch}{1.5}
begin{tabular}{ |p{2cm}|p{2cm}|p{2cm}|p{2cm}|p{2cm}|p{2cm}|p{2cm}|}
hline
multicolumn{7}{|c|}{The percentage of time spent by cell in each stage of cell cycle} \
hline
Samples & Interphase & Prophase & Metaphase & Anaphase & Telophase & Cytokinesis \
hline
Sample A & 95 & 3 & 0,9 & 0,5 & 0,3 & 0,3 \
hline
Sample B & 77 & 14 & 4 & 3 & 0,9 & 1,2 \
hline
end{tabular}\

b)

d) This difference of time between the two cell cycles can be explained by the age or the type of cells.
as it known the embryonic cells divide more rapidly than others body cells. While some others specialized cells as an adult nerve cells may never divide.

The difference of percentage of time spent by each cell sample in each stage of cell cycle shows that the two samples have different types or age.

The increase is size of the mole is an alarming issue and should be medically addressed immediately as the growth might be because of the uncontrollable growth of cancer cells.

X-rays and ultraviolet radiations in sunlight can sometimes damage the DNA of cells causing them to lose their ability to control cell division. Once the DNA is damaged, the cell growth can become uncontrolled forming cancerous masses in the body.

X-rays and ultraviolet radiations in sunlight can sometimes damage the DNA of cells causing them to lose their ability to control cell division.

X-ray radiations can damage the DNA of the developing fetus in pregnant women. This damaged DNA can lead to cancer, later in the life of the offspring.

Radiation can damage the DNA of cells causing them to lose their ability to control growth. This disability causes cancer. On the other hand radiation can be used to damage the DNA of cancer cells causing them to die and therefore eliminating their existence in the body to cure cancer. Note that the radiation that lead to cancer are often uncontrolled (that is from the sun) while using them to treat cancer is localized and controlled.

Yes, but I found that making flashcards and doing practice problems really reinforced the knowledge so now I understand mitosis.

b) The use of drugs that fight any illness help prolong life as they lessen the illness and can even heal patients from life-threatening illness

The direct UV light contact from tanning salons can damage skin cells and their ability to grow and reproduce, or worse, cause cancerous activity within the cell.

Galls are caused by bacteria, insects, fungi, and plant viruses

Scientists are using compounds that would target only cancerous cells within the body as a defense mechanism. Chemotherapy is also used to slow cell growth, however it effects all cells, not only the cancerous ones within the body

The sunscreen acts as a layer that prevents a certain amount of UV light from reaching skin cells, the higher SPF, the stronger the layer

Options are to surgically remove the cancerous cells, allow the pet to die as a result of the cancer, or put the pet down humanely

Viruses can cause warts by preventing feedback mechanisms that would slow the division of such affected skin cells

Diffusion is the spontaneous movement of a quantity from a region of high concentration to a region of low concentration