Assignment Help on Cell Biology Introduction

Part 1

1. Differences and similarities between prokaryotic and eukaryotic cells

The differences between prokaryotic and eukaryotic cells are following:

Some of the similarities between Prokaryotic and Eukaryotic cells are listed below:

Part 2

a) Specialized structures of sperm

Sperm is a Greek word that has a meaning seed. It is a male reproductive cell. They cannot be divided and have a fixed time span. After the unification by the egg cells at the time of fertilization, a new organism get developed known as totipotent Zygote. The sperm cells of human are haploid because of that its 23 chromosomes can connect with other 23 chromosomes of female egg in order to form diploid cell (Kierszenbaum and Tres, 2015). In the mammals, these sperms are born in the testicles while emerges out from the penis. A mature human sperm consist of snake like structure. The various parts of sperm and its functioning are described below:

Head :Its shape is spherical having a large nucleus. This also has a dome shaped acrosome that is existing on the nucleus.

• Function: Nucleus is containing all information about genes and more than half number of chromosomes. Acrosome present in the head are releasing a hyaluronidase enzyme that have power to destroy the hyaluronic acid present in the ovum and effectively enters into it.

Neck:This consist of centrioles that are proximal centriole and distal centriole.

• Function: Distal centriole forms axial filament of the sperm which are spreading up to the end of the tail.

Middle piece: It is tube like structure in which mitochondria are present.

• Functioning: This is known as power house of sperm as it provides energy to the sperm to swim in the genital tract of females (Gilfillan, Austin and Metcalfe, 2011).

Tail: This is the last part that contains axial filaments.

• Functioning: this helps sperm in doing movements.

source 1: SEMEN ANALYSIS - HOW TO INTERPRET A SEMEN ANALYSIS REPORT, SPERM COUNT, SPERM MOBILITY, SPERM MORPHOLOGY. TESTING THE MAN - SEMEN ANALYSIS , 2017

b) Specialized structures that allow a red blood cell to carry out its role

Red blood are also known as erythrocytes and these are present in large quantity in comparison to other cells like plasma, white blood cells and platelets. This contains a unique shape for performing their functioning. It has a flattened and biconcave disc shape. It do not contain any nuclei or mitochondria (Cheng, 2013). Their production occurs at the bone marrow and has a life time of minimum 120 days. Red blood cells are quilted or thicker at the edges while they are thinner at the centre. Its main function is to carry oxygen throughout the tissue from the lungs and then transporting back carbon dioxide from the cells to lungs.

2. The fluid mosaic model

Scientist use fluid mosaic model of cell membrane to describe about its functioning and parts. The cell membrane is made up of commonly three things that are Phospholipids, Cholesterol and Proteins. These are described below:

• Phospholipids:It has two important part namely head and tail. Head is phosphate molecule and are hydrophilic that is attracted to water (Flannagan, Jaumouillé and Grinstein, 2012). While tails are composed of fatty acids that repels water.
• Cholesterol:This is a type of steroid which assists in regulation of molecules from incoming and outgoing from cell.
• Proteins:Cell is made up of two types of proteins namely integral and peripheral protein. Integral one aids in transportation of large molecules like glucose across the cell membrane. While other peripheral proteins are not extended across cell membranes but are connected to end of integral proteins and assist in communication.

The purpose of cell membrane is to hold several parts of cell together and to protect it from the external environment of cell (Gilfillan, Austin and Metcalfe, 2011). It also take care of regulation and do not loose large number of nutrients and takes too many ions effectively. This also do the job of protecting from harmful things.

3. What forms of transport occur, and how are they important?

Active and passive transport are two biological process that are responsible of moving oxygen, water supply and nutritive particles into cell membrane and also assist in removing waste matters from it. Active one needs chemical energy as it allows movement of biochemicals from the areas of low concentration to the higher one (Strickland and et. al., 2012). While passive transport do the opposite work by moving biochemicals from high concentrated region to lower one. So, it does not need any energy. Active and passive transport is very important as it controls the entry and exits of different materials. This transport of material is to and fro and are dominated by the permeable cell membrane.

4. Discuss how mitosis and meiosis occur while explaining how they are different

Mitosis can be defined as cycle through which eukaryotic cells under go. During this process, the cell is duplicating its DNA and are separating it into genetically similar cells. The stages of Mitosis are described below:

• Prophase: In this stage, membrane that are covering the nucleus starts dissolving and the chromatin are getting condensing into discrete chromosomes.
• Metaphase: Chromosomes aligns here in the equator and centromeres are moving to the pole in order to prepare for detachment.
• Anaphase:In this phase here separated chromosomes are getting pulled by centromeres. This gets completed when the proteins that are binding the chromatids together are split. Now the chromosome pairs are present at other end of the cells (Mandelkow and Mandelkow, 2012).
• Telophase:New nuclear membrane are creating surrounding the new sets of chromosomes.

Meiosis:This is a special cell separation cycle that is used to divide gamete or sex cells. The stages of meiosis are following:

• Meiosis stage I: This is very much alike as mitosis and starts with prophase I, where the crossing over of chromosome are occurring (Prescott, 2012).
• Metaphase I:Cell then are moving to metaphase I, where the chromosomes are lining up in the equatorial plane in order to prepare for segmentation.
• Anaphase I:Here cells starts dividing itself after separation of chromosomes.
• Telophase I: At this phase the division gets finished and each cells achieves its own chromosome pairs.
• Meiosis II : The mechanical processing are same but are producing two regular cells in comparison to four haploid cells. The phases are somehow same Prophase II, Metaphase II, Anaphase II and Telophase II.

The main difference between meiosis and mitosis is that mitosis are occurring in every eukaryotic cells (Davis and Chin, 2012). On the contrary, meiosis is a exceptional type of mitosis that are occurring only in gamete or sex cells. Mitosis are creating two same cells from single mother cells while meiosis are generating four genetically specific haploid cells from one mother cell.

Conclusion

From the above based report it has been concluded that the cell biology has covered a vast range of processes. There are two types of cells namely eukaryotic cells and prokaryotic cells. The structure and role of human sperm is described here. Additionally the structure and functioning of red blood cell is also highlighted. The fluid mosaic model are explained with three parts of cell membrane that are Phospholipids, Cholesterol and Proteins.

You may also like to read:

• Artificial Intelligence
• FOOD RESEARCH PROJECT ON RAW FOOD
• Grain Forecast: Frost hits Western Australian crop production
• Geocaching Devices

References

Books & journal

• Cheng, T. C., 2013. Marine Biomedical Research Program and Department of Anatomy (Cell Biology) The Medical University of South Carolina Charleston, South Carolina. Invertebrate Blood: Cells and Serum Factors. 6. p.111.
• Davis, L. and Chin, J. W., 2012. Designer proteins: applications of genetic code expansion in cell biology. Nature reviews. Molecular cell biology. 13(3).p.168.
• Flannagan, R. S., Jaumouillé, V. and Grinstein, S., 2012. The cell biology of phagocytosis. Annual Review of Pathology: Mechanisms of Disease. 7.pp.61-98.
• Gilfillan, A. M., Austin, S. J. and Metcalfe, D. D., 2011. Mast cell biology: introduction and overview. Mast Cell Biology.pp.2-12.
• Kierszenbaum, A. L. and Tres, L., 2015. Histology and Cell Biology: An Introduction to Pathology E-Book. Elsevier Health Sciences.
• Mandelkow, E. M. and Mandelkow, E., 2012. Biochemistry and cell biology of tau protein in neurofibrillary degeneration. Cold Spring Harbor perspectives in medicine. 2(7). p.a006247.
• Prescott, D. M. ed., 2012. Cell Biology A Comprehensive Treatise V3: Gene Expression: The Production of RNA's (Vol. 3). Elsevier.
• Strickland, D. and et. al., 2012. TULIPs: tunable, light-controlled interacting protein tags for cell biology. Nature methods. 9(4).pp.379-384.

UPTO50%

Avail The Benefit Today!

To View this & another 50000+ free

Enter Email

Submit