CANCER diseases

Cancer is one of the most dreaded diseases of human beings and is a major cause of death all over the globe .More than a million Indians suffer frkm cancer and a large number of them die from it annually.the mechanisms that underlie development of cancer or oncogenic transformation of cells, its treatment and control have been some of the most intense areas of resarch in biology and medicine .
In our body , cell growth and differntiation is highly controlled and regulated .

  Causes of canser :- Transformation of normal cells into cancerous neoplastic cells may be induced by physical , chemical or biologyical agents .this agents are called carcinogens .
  Cancer detection and diagnosis:- Early detection of cancer is essential as it allows the diseases to be treated successfully in many cases.cancer detection is based on biospy and histopthaological studies of the tissue and blood and bone marrow tests for increased cell counts in the case of leukemias.
  Treatment of Cancer:- the common approaches for the treatment of cancer are surgery, radiation therapy and immunotherapy.in radiotherapy, tumor cells are irradiated lethally, taking proper care of the normal tissues surrounding the tumor mass.

About HIV/AIDS

The word AIDS stand for Acquired Immuno Deficiency Syndrome.This means deficiency of immune system, acquired during the lifetime of an individual indicating that it is not a congential disease.'Syndrome' means a group of symptoms.AIDSwas first reported in 1981 and in the last twenty-five years or so , it has spread all over the world killing more than 25 million person .
    AIDS is caused by the Human Immuno deficiency Virus (HIV),a member of a group of viruses called retrovirus, which have an envelope enclosing the RNA genome.Transmission of HIV- infection generally occurs by :-

1) sexual contact with infected persion,
2) by transfusion of contaminated blood products ,
3)by sharing infected needles as in the case of intravenous drug abusers and
4)From infected mother to her child through placenta.

         So , people who are at high risk of gettinh this infestion includes- individuals who have multiple sexual partners , drug addicts who take drugs intravenously, individuals who required repeated blood transfusions and children born to an HIV infected mother .It ia most inportant to note that HIV/ AIDS is not spread by mere touch or physical contact; it spreads only through bosy fluids .

Introduction of Biology

             As we all know our universe is made up of stars,galaxies,asteraids and planets. In once small corners of the universe lies a precious and beautiful world on the planet earth.Life is found on the planet earth and basically the study of life is called biology.The term biology originate from the two greek word one is “BIOS” which means life and “LOGUS” which  means study.When we say life is doesn’t only means humans we have to consider plants,animals,birds and various forms of micro organisms etc.When we study the biology we get the answer about living and nonliving organisms.

An organisms is a living entity consisting of one cell. Example: bacteria or several cell(animals,plants and fungi).Aspects of biological science range from the study of molecular mechanism of cells,to the classification and behaviour of organisms.how species evolve and intraction  between  ecosystem.BIOLOGY and other  SCIENCES

Biology is often studied in conjunction with other sciences,such as mathematics and engineering and even social sciences.Here are few examples of biological science:

• Bio-engineering is the application of engineering principles to biology principles and vice versa.According to the university of california berkeley
•  the  20th and 21th centuries may be known to future generations as the beginning of the ‘BIOLOGICAL REVOLUTION” beginning with watson and crick explanning the structure and function of DNA in 1953.

RNA

RNA was the first genetic material .there is now enough evidence to suggest that essential life processes,(such as metabolism ,translation,splicing, etc ), evolved around RNA .RNA used to act as a genetic material as well as a catalyst (there are some important biochemical reaction in living systems that are catalyst by RNA catalyst and not by protein enzymes) . But , RNA being a catalyst was reactive and hence unstable .therefore ,DNA has a evolved from RNA with chemical modifications that make it more stable ..DNA being double standard and having complimentary strand further resists changes by evolving a process of repair.

• there are three major types of  RNAs : mRNA (messenger RNA ),tRNA (Transfer RNA ), And rRNA(ribosomal RNA )..
  

• All three RNAs are needed to synthesise a protein in a cell.
• the mRNA provides the template,tRNA brings aminoacids  and reads the genetic code, and rRNA play  structural and catalystic role during translation …

DNA

DNA is a long polymer of deoxyribonucleotides.  The length ofDNA is usually defined as number of nucleotides (or a pair of neucleotide reffered to as base paris ).DNA as an acidic substance  present in nucleus was first identified by “Friedrich Meischer in 1869. DNA is a long molecule that contains our unique genetic code .like a recipe book it holds the instraction for making all proteins in our bodies..

• DNA contains four basic building blocks or “bases”….Adenine (A) , Cytosine (C) , Guanine(G) ,and Thymine(T)…