Give one significant difference between primary lymphoid organs and secondary lymphoid organs. Give one example of each.

Feature Primary lymphoid organ Secondary lymphoid organ Function and Example The primary lymphoid organs are the site where lymphocytes are produced and mature. Example: Bone marrow and Thymus Secondary lymphoid organs provide the sites for the interaction of a specific WBC called lymphocytes with antigen. Example: Spleen and Lymph nodes

List four effects of alcoholism on human health.

The effects of alcoholism on human health can be immediate or far-reaching. Changes in sleeping pattern, fluctuation in weight, loss of appetite and lack of hygiene are some immediate effects of alcoholism. Chronic use of alcohol damages the nervous system and also causes damages to the liver and heart. The use of alcohol during pregnancy causes adverse effects on the foetus. An alcoholic person has a high risk of infections like AIDS and hepatitis B.

List four reasons for drug addiction.

Adolescence is a very vulnerable phase of the mental and physiological development of an individual. They use drugs and alcohol to have fun or to flaunt society. They take drugs due to the following reasons: Curiosity and need for adventure, excitement and experiment. Due to social and peer pressure. To overcome hardships, apathy, i.e., lack of interest in day to day life. To avoid stress, depression and frustration.

Name the antibody which is most effective in allergies.

Allergy is the hypersensitivity reaction of a person to some foreign substance coming in contact with or entering the body. Certain common allergic reactions, such as hay fever, asthma, and hives, are linked to an antibody produced by B lymphocytes called immunoglobulin E (IgE).

Explain two characteristics of cancer cells.

The cancer cells exhibit the following characteristics: The cancer cells grow and divide at an abnormally rapid rate. The cancer cells are poorly differentiated, and have abnormal membranes, cytoskeletal proteins, and morphology.