ISLAND OF SRI LANKA

Sri Lanka is an island which is surrounded by the Indian Ocean. It measures about 65525 square kilometers. It is rich with many natural resources including fresh water, rain forests and natural beauty.
Sri Lanka has a three thousands year’s long written history. Anuradhapura, Polonnaruwa and Kandy were the main historical kingdom. Still there is thousands of remaining of evidence of a great civilization. The civilization of the Sri Lanka built upon the agriculture and irrigation. The knowledge on irrigation and agriculture that past Sri Lankan is a mystery even in today.
At present it is a democratic socialistic country. Now she is passing her 60th year after obtaining independence from British crown. Majority of Sri Lankan are Sinhalese which makes up the 75 percent of total population where as minority comprises of Tamils, Muslims and few other nationalities. The main religion is Buddhism and 70 percent of Sri Lankans are Buddhists. Other religions are Hindu, Islam and Christianity. Majority of Sri Lankans are living with peace and harmony.
During last three decades we are suffering from LTTE terrorism. More than seventy thousands lost their lives because of this problem. Several political leaders had tried to solve this problem by discussing with LTTE but all attempts were end up in vein. Now there is a rising idea among majority of Sri Lankan that this problem should be solved by eradicating the LTTE terrorists.
Without any doubt Sri Lanka is an one of most beautiful country in the world and we all hope that she will have happy and prosperous future.

Cancer IV

Cancer is usually classified according to the tissue from which the cancerous cells originate, as well as the normal cell type they most resemble. Definitive diagnosis usually requires the histological examination of a tissue biopsy specimen by a pathologist, although the initial indication of malignancy can be symptoms or radiographic imaging abnormalities. Most cancers can be treated and some cured, depending on the specific type, location, and stages. Prognosis in many cases is most influenced but the staging of the disease, although histological grading and molecular markers are often useful in establishing prognosis, as well as determining individual treatments. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for different verities of cancers. There has been significant progress in the development of drugs that target specific, detectable molecular abnormalities in certain, and which minimize damage to normal cells.

Cancer III

Genetic abnormalities may promote malignant behavior in cells through their effects on two general classes of genes. Cancer – Promoting oncogenes are often activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments. Tumor Suppressor Genes are often inactivated in cancers cells, resulting in the loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system.

Cancer II

Nearly all cancers are known to be caused by the accumulation of abnormalities in the genetic material of the transformed cells. These abnormalities may be due to the effect of environmental agents, or carcinogens, such as tobacco smoke radiation, chemicals, or infectious agents. Other cancer – promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or may be inherited, and thus present in all cells from birth. Complex interactions between carcinogens and the host genome may partially explain why only some patient get cancer after exposure to a known carcinogen. New aspect of the genetics of cancer pathogenesis , such as DNA methylation , and microRNAs are increasingly being recognized as important.

Cancer I

Cancer is a disease characterized by a population of cells that grow and divide without respect to normal limits, and that invade in to adjacent tissues, or spread to distant anatomic sites through a process called metastasis. These life – threatening properties of cancer are referred to as malignant, and differentiate cancers from benign tumors , which are self – limited in their growth and do not invade or metastasize. Cancer may affect people at all ages, but risk for the more common verities tends to increase with age. It is one of the principal causes of death in developed countries.

Meiosis II

During meiosis, the genome of a diploid germ cell, which is composed of long segments of DNA packaged into chromosomes, undergoes DNA replication followed by two rounds of division, resulting in haploid cells called gametes. Each gamete contains one complete set of chromosome, or half of the genetic content of the original cell. These resultant haploid cells can fuse with other with other haploid cells of the opposite sex or mating type during fertilization to create a new diploid cell, or zygote. Thus, the division mechanism of meiosis is a reciprocal process to the joining of two genomes that occurs at fertilization. Because the chromosomes of each parent undergo genetic recombination during meiosis, each gamete, and thus each zygote, will have a unique genetic blueprint encoded in its DNA. In Other words, meiosis and sexual reproduction produce genetic variation. Meiosis uses many of the same biochemical mechanisms employed during mitosis to accomplish the redistribution of chromosome. There are several features unique to meiosis, most importantly the pairing and genetic recombination between homologous chromosomes.

meiosis i

Haploid and monoploid
Gamete
Overview of microbiology
Classification of medically important bacteriae
structure of bacterial cell
How do bacteria cause diseases (Pathogenesis)?
Host defenses against bacteria
Growth and genetics of bacteria
Detection of microorganisms (Diagnostic tests)
Bacteriae which make the normal flora

Meiosis I

In biology meiosis is the process by which one diploid eukaryotic cell divides to generate four haploid cells often called gametes. The word “ meiosis” comes from the Greek meioun, meaning “ to make smaller”, Since it results in a reduction in chromosome number in the gamete cell.

Meiosis is essential for sexual reproduction and therefore occurs in all eukaryotes, including single – celled organisms that produce sexually.

• Haploid and monoploid
• Gamete
• Overview of microbiology
• Classification of medically important bacteria
• structure of bacterial cell
• How do bacteria cause diseases (Pathogenesis)?
• Host defenses against bacteria
• Growth and genetics of bacteria
• Detection of microorganisms (Diagnostic tests)
• Bacteria which make the normal flora
• Normal bacterial flora of the skin
• Skin, soft tissue and wound infections and treatment

Mitosis

Mitosis is process in which a cell duplicate its chromosome to generate two, identical cells it is generally followed by cytokinesis which divides the cytoplasm and cell membrane :this result in two identical cells with an Equal distribution of organelles and other cellular components mitosis and cytokines jointly defining the mitotic (M) phase of the cell cycle the division of the mother cell in to two sister cells each with the genetic equivalent of the parent cell. Mitosis occurs most often in ekukaryotic. cells in multicellular organism, the somatic cells undergo mitosis while germ cells cells destined to become sperm in males or ova in famels divideby related process called meiosis.

Rate Of Multiplication In Bacteria

Bacteria can divide every twenty to thirty minuets . this gives to bacteria remarkable power of multiplication. Consider a single bacterium. After 24 hours there would be 2⁴⁸ or 2.81 X 10¹⁴ bacteria . this is within the range of the number of Eucharistic cells in the human body.

This has obvious implications for dealing with bacterial diseases because sine bacteria multiply so rapidly it is critical to treat bacterial diseases Swiftly and as completely as possible .Fortunately bacteria rarely are able to sustain this high rate of multiplication for long because of limitations in nutrient availability and various bacteria feeding organism (bacteriovores) and bacterial infecting viruses (bacteriophages).

Binary Fission II

The diagram at 1 shows a bacterial cell. The cell wall and membrane are in red, the bacterial chromosome in blue, the cytoplasm in light green. The yellow dot represents a point of attachment of the chromosome to cell membrane.

Typically bacterial chromosomes consist of a single loop of DNA, often called circular DNA. Eukaryotes have a linear DNA molecule.

Duplication of the DNA during this Step bacterial chromosome replicates leading to two identical chromosomes attached to separate point of attachment. The cell begins to divide, each cell with an identical chromosome. The result is two identical daughter cells.

Binary Fission

Prokaryotes such as bacteria use a relatively simple from of cell division called binary fission. My next articles are on four steps of this diagram.

Somatic eukaryotic cells

Structure of a Somatic eukaryotic cell

Somatic eukaryotic cells

• Mitosis: the division of the nucleus. Separation the duplicated genome into two sets identical to parent’s .
• Cytokinesis: the division of the cytoplasm, separating the organelles and other cellular components .
• Meiosis: the division of the nucleus in sex cells , making one cell into four sex cells identical to the parent sex cell.

prokayotic cell
Haploid and monoploid
Gamete
Overview of microbiology
Classification of medically important bacteriae
Structure of bacterial cell
How do bacteriae cause diseases (Pathogenesis)?
Host defenses against bacteriae
Growth and genetics of bacteriae
Detection of microorganisms (Diagnostic tests)
Bacteriae which make the normal flora

Prokaryotic Cells

Prokaryotic cells Are simpler in structure when compared to eukaryotic cells. They contain non-membranous organelles, lack a cell nucleus and have a simplistic genome:only one circular chromosome of limited size .therefore Prokaryotic cell division a process known as binary fission is fast .the chromosomes is duplicated prior to division .the two copies of the chromosome attach to opposing sides of the cellular membrane. Cytokinesis, the physical separation of the cell, occurs immediately

Three Types Of Cell Division

Cells are classified into two categories: simple, non-nucleated prokaryotic cells, and complex nucleated eukaryotic cells. By dint of their structural differences, eukaryotic and prokaryotic cells do not divide in the same way. Furthermore, the pattern of cell division that transforms eukaryotic stem cells into gametes (sperm in males or ova in females) is different from that of eukaryotic somatic(non-germ)cells.

Haploid and monoploid
Gamete
Overview of microbiology
Classification of medically important bacteriae
Structure of bacterial cell
How do bacteriae cause diseases (Pathogenesis)?
Host defenses against bacteriae
Growth and genetics of bacteriae
Detection of microorganisms (Diagnostic tests)
Bacteriae which make the normal flora

Cell Division III

The primary concern of cell division is the maintenance of original cell's genome. Before division can occur, the gnomic information which is stored in chromosomes must be replicated, and the duplicated genome separated cleanly between cells. A great deal of cellular infrastructure is involved in keeping gnomic information consistent between "generations

Cell Division I

Cell devision is a process by which a cell, called the parent cell, divides into two cells, called dauter cells. Cell division usually a small segment of a large cell cycle. In meiosis however, a cell is permanently transformed and cannot divide again. Ceell division takes from 10 minutes to 6 hours to complete.