CBSE Class 12 Biology Human Health and Diseases Flow Chart

This Class 12 Biology flow chart on Chapter 8, Human Health and Diseases, summarises health and its factors, the types of diseases with their causes and control measures, the two types of acquired immunity, and the types of immune responses.

1. HEALTH

Health is a state of complete physical, mental and social well-being.

2. FACTORS AFFECTING HEALTH

1. Genetic factors, for example sickle cell anaemia.
2. Life style factors, for example obesity.
3. Infections, for example influenza.

3. TYPES OF DISEASES

Infectious (communicable) diseases
Examples: leprosy, common cold.
Transmitted by air, water, physical contact and animals.
Types of infectious diseases: viral, bacterial, fungal, worm (helminth) and protozoan diseases.
Control measures: balanced diet, good personal hygiene, awareness about diseases, vaccination, hygienic food and water.

Non-infectious (non-communicable) diseases
Causes: stress, no or less physical activity, genetic factors, unsuitable diet, wrong life style and exposure to carcinogens.
Control measures: stress management, physical exercise, balanced diet, avoiding drugs, alcohol and tobacco.

4. TYPES OF ACQUIRED IMMUNITY

Active immunity
The antibody is produced within one's own body when exposed to an antigen. It is long lasting, does not cause allergy, but takes time to activate. Example: exposure to chicken pox, measles, etc.

Passive immunity
Antibodies are transferred from another individual. It is not long lasting, sometimes causes allergy, but provides immediate relief. Examples: colostrum (IgA) given to a baby, and antitoxin given for snake bite. Vaccine given for tetanus.

5. TYPES OF IMMUNE RESPONSES

Humoral immunity
The response is produced by antibodies made by B lymphocytes, and is found in blood and lymph.
Antibody types: IgA, IgM, IgE and IgG.
An antibody has two small light chains and two longer heavy chains (H₂L₂).

Cell-mediated immunity
The response is produced by T lymphocytes. It plays a role in organ transplantation.

Important Questions for NCERT Class 12 Biology Human Health and Diseases

Ques. Which one of the following is not correctly matched?
(a) Glossina palpalis - Sleeping sickness
(b) Culex pipiens - Filariasis
(c) Aedes aegypti - Dengue fever
(d) Anopheles culicifacies - Leishmaniasis 

Answer: D

Ques. Salmonella is related with
(a) typhoid (b) polio
(c) T.B. (d) tetanus. 

Answer: A

Ques. Which is the most infectious disease?
(a) Hepatitis-B (b) AIDS
(c) Amoebiasis (d) Malaria 

Answer: A

Ques. Which is showing accurate pairing?
(a) Syphilis - Treponema pallidum
(b) AIDS - Bacillus conjugalis
(c) Gonorrhoea - Leishmania donovani
(d) Typhoid - Mycobacterium leprae 

Answer: A

Ques. Saline solution is given to patients of cholera because
(a) Na+ prevents water loss from body
(b) NaCl function as regulatory material
(c) NaCl produces energy
(d) NaCl is antibacterial. 

Answer: A

Ques. Botulism caused by Clostridium botulinum affects the
(a) lymph gland
(b) central nervous system
(c) spleen
(d) intestine.

Answer: B

Ques. Typhoid fever is caused by
(a) Shigella (b) Escherichia
(c) Giardia (d) Salmonella. 

Answer: D

Ques. Diphtheria is caused by
(a) nematodes (b) bacteria
(c) virus (d) none of these.

Answer: B

Ques. Which of the following diseases is now considered completely eradicated from India?
(a) Small pox (b) Poliomyelitis
(c) Plague (d) Kala-azar 

Answer: A

Ques. Which of the following symptoms indicate red sickness?
(a) Nausea and loss of hair
(b) Ulcerated skin, nausea and loss of hair
(c) Red and ulcerated skin
(d) Nausea and anaemia 

Answer: B

Ques. Which of the following pair of diseases is caused by virus?
(a) Rabies, mumps (b) Cholera, tuberculosis
(c) Typhoid, tetanus (d) AIDS, syphilis 

Answer: A

Ques. Which one of the following pairs is not correctly matched?
(a) Syphilis – Trichuris trichiura
(b) Sleeping sickness – Trypanosoma gambiense
(c) Dengue fever – Arbovirus
(d) Plague – Yersinia pestis 

Answer: A

Ques. Which of the following causes plague?
(a) Trichinella spiralis
(b) Salmonella typhimurium
(c) Yersinia pestis
(d) Leishmania donovani 

Answer: C

Ques. Which one of the following does correctly match a sexually transmitted disease with its pathogen?
(a) Syphilis-Treponema pallidum
(b) Gonorrhoea-Entamoeba histolytica
(c) Urethritis-Bacillus anthracis
(d) Softsore-Bacillus brevis

Answer: A

Ques. Schizont stage of Plasmodium occurs in human
(a) erythrocytes (b) liver cells
(c) erythrocytes and liver cells
(d) erythrocytes, liver cells and spleen cells. 

Answer: C

Ques. If all ponds and puddles are destroyed, the organism likely to be destroyed is
(a) Leishmania (b) Trypanosoma
(c) Ascaris (d) Plasmodium. 

Answer: D

Ques. Give the correct matching of causative agent/germ and disease.
(a) Anopheles – Malaria
(b) Leishmania – Sleeping sickness
(c) Glossina – Kala-azar
(d) Wuchereria – Filariasis 

Answer: D

Ques. The part of life cycle of malarial parasite Plasmodium vivax, that is passed in female Anopheles is
(a) sexual cycle
(b) pre-erythrocytic schizogony
(c) exoerythrocytic schizogony
(d) post-erythrocytic schizogony. 

Answer: A

Ques. African sleeping sickness is due to
(a) Plasmodium vivax transmitted by tse-tse fly
(b) Trypanosoma lewsii transmitted by bed bug
(c) Trypanosoma gambiense transmitted by Glossina palpalis
(d) Entamoeba gingivalis spread by housefly. 

Answer: C

Ques. Malignant tertian malarial parasite, belongs to class
(a) Plasmodium falciparum
(b) P. vivax
(c) P. ovale
(d) P. malariae. 

Answer: A

Ques. Who discovered Plasmodium in RBC of human beings?
(a) Ronald Ross (b) Mendel
(c) Laveran (d) Stephens

Answer: C