Cell Reproduction

Introduction

All cells are a derivative of other cells. Cell reproduction is the course by which a cell is divided to form two cells, which are similar to each other. The cells that have the function of reproduction in living things are known as gamete cells (Romano, 2005). In animals, the gamete cells are ova and sperm while in plants reproduction occurs in the pollen and the ovules. In living things, there are two different types of cells based on the structure. A cell is either prokaryotic or eukaryotic. Prokaryotic cells divide in a progression referred to as binary fusion while eukaryotic cells divide by means of either meiosis or mitosis.

Mitosis

Mitosis is the course by which a cell multiplies and then reproduces to form two other cells with similar genetic make-up (Romano, 2005). Similarly, the two cells will be identical to the parent cell. This process goes through four stages prophase, metaphase, anaphase and telophase. In prophase, the chromatin multiples to give two chromatids. These chromatids align themselves in the center of the cell in metaphase (Alcamo & Krumhardt, 2004). In anaphase, the chromatids disconnect at the center and move apart. Finally, in telophase the cell membrane surrounds the disconnected chromatids to form two similar cells.

Meiosis

This is a special process as it enables eukaryotic cells to reproduce sexually and expand the genomes (Alcamo & Krumhardt, 2004). In animals, it generates more sperms or ova while in plants it creates more spores. Meiosis result is four cells, which have a different genetic make-up from the parent cell. Cell division occurs twice, meiosis one and meiosis two. In the first part, the cell is divided to form four chromatids. In meiosis two, the chromatids are further divided in a process that is comparable to mitosis.

Differences between normal cells and cancer cells

One of the key differences between normal and cancer cells is that cancer cells will continue to replicate even though the process is over while normal cells have the ability to stop reproduction (Hardman & Stensel, 2003). Cancer cells fail to acknowledge the warning sign of the neighboring cells that it is time to stop while normal cells respond to the signs. While the normal cells remain at the right tumour, cancer cells will disconnect from the tumour and find its way to other sections of the body. Normal cells have mechanism that destroys them in case of uncharacteristic cell differentiation while cancer cells will survive even if they are immature (Hardman & Stensel, 2003). Lastly, normal cells will develop and specialize while cancer cells will not.

Which type of tissue would have a higher mitotic index: normal tissue or cancerous tissue?

Cancerous cells have the ability to reproduce even if the process is over. Their means of cell reproduction is out of control because they fail to react to contact inhibition. For that reason, cancerous tissues will display a high mitotic index (Rieger, 2001). Compared to the normal tissue, the number of cells undergoing mitosis at a given period is higher in cancerous tissues.

Which type of cancer shows the most aggressive growth?

The small cell cancer of the lung demonstrates the most antagonistic growth. These malignant cells have the ability to develop speedily and move to other parts of the body in the initial stages. The primary malignant cells move from the lymph node to the blood vessels where it is passed to other body parts such as kidney, brain, bones and the adrenal glands (Rieger, 2001).

References:

Alcamo, I. E., & Krumhardt, B. (2004). Anatomy and physiology the easy way. New York, NY: Barron’s.

Hardman, A., & Stensel, D. (2003). Physical activity and health: the evidence explained. London, UK: Routledge.

Rieger, P. T. (2001). Biotherapy: A comprehensive overview. Boston, MA: Jones and Bartlett.

Romano, A. (2005). Cell specialization and reproduction: Understanding how cells divide and differentiate.New York, NY: Rosen Publishing Group.