• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13

Defence against Disease.

Extracts from this document...


Defence against Disease Biology assignment Due date: 27th June, 2003 Suzanne Jensen Concept Outline 1. Immunity * Immune system * Non-specific immunity * Specific immunity * Antibodies 2. Non-Specific Immunity A. The first line of defence * Figure 8.5 * Skin * Mucous Membranes * Natural flora B. The second line of Immunity * Phagocytes * Killer cells * Neutrophils * Monocytes * Complement Proteins * Interferon * Inflammation * Figure 8.9 * Histamine * Pus 3. Specific Immunity A. Cells involved in specific immunity * Lymphocytes * Bone marrow * B cells * T cells * Figure 8.10 B. How do B cells and T cells identify foreign material? * Major histocompatibility complex(MHC) * Class 1 markers * Class 2 markers C. Many kinds of B cells * Immunoglobulins D. The clonal-selection theory of antibody production * Clone * B-memory cells * Figure 8.14 E. How much antibody is produced? * Figure 8.15 F. Structure of an antibody * Humoral Immunity * Table 8.2 G. Different kinds of antibodies * Figure 8.17 H. T cells * Helper T cells * Cytotoxic T cells I. T cells and B cells travel around the body * Lymph * Figure 8.20 4. Acquiring Specific Immunity A. Active Immunity B. Natural active Immunity * Sub-clinical infection C. ...read more.


D. The clonal-selection theory of antibody production * The B cell selected by the antigen reproduces rapidly to give rise to a number of identical cells. Each of these cells also reproduces rapidly to produce a large clone of cells. * Some of the B cells produced differentiate into other cells called B-memory cells. B memory cells also have the same antibody-antigen specificity as the parent B cell. Plasma cells survive for only a few days but memory cells can survive for several years. * Figure 8.14 E. How much antibody is produced? * On a second infection the concentration of antibodies rises much more rapidly then during the primary response and many more antibodies are released. * Figure 8.15 F. Structure of an antibody * An antibody molecule had four polypeptide chains, two long heavy chains and two shorter light chains joined together * Immunity involving antibodies in body fluids is called humoral immunity * Table 8.2 G. Different kinds of antibodies * IgM and IgG antibodies activate macrophages and the complement system and are particularly active against bacteria and their toxins. IgA antibodies play an important role in surfaces that are vulnerable to infection and are present in the mast cells which release histamines. H. T cells * After encountering their specific antigens, T cells reproduce rapidly in the same way as B cells and T-memory cells also form. ...read more.


Immune deficiency diseases * Immune deficiency is a malfunction or a deficiency in one or more components of the immune system. Immune deficiency disorders can be inherited or may develop as a result of some other disease. E. Acquired immune deficiency syndrome (AIDS) * It is generally accepted that acquired immune deficiency (AIDS) is caused by the human immunodeficiency virus (HIV). This virus only infects cells carrying a particular protein marker. The marker is found mainly on mature helper T cells and to a lesser extent on macrophages. * Figure 8.38 * The development of the disease after infection with HIV is variable * Once the serious symptoms of AIDS appear, death usually follows within about two years. F. Do plants have an immune system? * Most plants are resistant to pathogens * Mechanical barriers- The silicon content of some leaves makes them particularly resistant to the degrading enzymes of pathogens. If a disease-causing organism penetrates the outer layers, and the stomata in particular can be a point of entry; layers of thickened cells form in many cases. This gives rise to abnormal swellings at the infection site. These swellings are called galls. * Galls are caused by pathogenic organisms, including insects and nematode worms. * Chemical barriers- Some plants resist disease by producing chemicals that act as antibiotics * Chemicals that have a defence role in plants include: resins, tannins and phenolic substances ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Molecules & Cells essays

  1. Marked by a teacher

    "To Clone or Not to Clone- That is the Question".

    4 star(s)

    In the chemical cultures, there would be a dose of cytochalasin B. This is a substance that stops the formation of the Polar Body cell, a cell that normally forms before fertilization and removes half the genes from the cell in preparation for the sperm to supply the other half.

  2. Immune System. The Non-Specific responses react to any kind of damage by mast cells ...

    Lymph fluid from most tissues or organs flows through one or more lymph nodes, where it is filtered and cleaned, before draining into the venous blood stream.

  1. The Immune system.

    They help to destroy bacteria, neutralizing their toxins and also clear away antigen and antibody complexes that trigger a cascade of complement proteins. They also attach themselves to diseased organisms. The proteins penetrate the cell membrane of the diseased organism which then bursts and dies as intracellular fluids flow in.

  2. Liver and its role

    These fair tests are listed below: * Volume of the lipase: As I have stated in the scientific background, the lipase catalyses the reaction of breaking down of fats. This means that the higher the volume of the enzyme used the more reactions there will be (up to some point

  1. Growing Micro-organisms

    Temperature affects the growth of the yeast cells because in low temperatures the process and chemical reactions in the solution are slowed down and in how temperatures the yeast cells are killed, they're a lot like human, they can only handle certain temperatures.

  2. Enzymes and Micro-organisms

    This is used to make large amounts of microorganisms. Solid culture media is usually found in the form of an ager that's usually used in small industries and in colleges (in this project we will be experimenting with solid agers).

  1. How do Cytotoxic T cells recognise and kill virally infected cells?

    All cells have major histocompatibility (MHC) complexes on their surfaces. Class 1 MCH molecules express a sample portion of the proteins made within the cell, forming a groove around this peptide molecule. Under normal cellular conditions this peptide will be a fragment of the usual cell constituents.

  2. Immunity. The immune system is a group of cells and organs that defend ...

    Humoral immunity is a type of immunity which is conferred through the release of antibodies which are used to target cells for destruction by the body when these cells are viewed as potentially dangerous. This type of immunity is a complement to cellular immunity, in which cells release toxins to

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work