CBSE Class 12th Exam Date:17 Feb' 26 - 17 Feb' 26
The NCERT Solutions for Class 12 Biology Chapter 7 Human Health and Disease discusses various forms of immunity. It includes innate and acquired immunity and how the immune system fights infections. Common diseases such as bacterial, viral, and fungal, and lifestyle diseases like cancer and drug addiction, are covered. The NCERT Solutions present the topics in a clear and organised way. This makes it easier for students to understand the concepts and score well in exams.
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                Through the study of the Human Health and Disease Class 12 question answer, students can understand the cause of different diseases and how to protect themselves. The Human Health and Disease Class 12 Questions and Answers PDF is also important for NEET preparation, as it covers topics that are frequently asked in exams. The NCERT Solutions for Class 12 Biology provide explanations of all the questions in a step-by-step manner. For quick and easy revision, the solutions serve as a perfect resource to strengthen preparation and boost confidence before exams.
Students can download the PDF of the Human Health and Disease chapter from the link given below. The Human Health and Disease Class 12 Questions and Answers PDF includes answers to all the questions in a well-understandable manner.
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The detailed answers to all the questions of this chapter are given below. By going through the Class 12 Biology Chapter 7 Human Health and Disease question answers, which are prepared according to the latest NCERT guidelines, students can gain knowledge about diseases.
Answer:
To avoid infectious diseases, the following public health measures can be implemented:
Ques 2. In which way has the study of biology helped us to control infectious diseases?
Answer:
The study of biology has contributed greatly to the prevention of diseases in various ways:
Ques 3. How does the transmission of each of the following diseases take place?
A) Amoebiasis
Answer:
Amoebiasis - It is transmitted through the consumption of water and food contaminated by amoebic cysts.
B) Malaria
Answer:
Malaria - It is transmitted from one person to another using the female Anopheles mosquito. When a female Anopheles mosquito bites an infected person, it ingests Plasmodium parasites with the blood. When it later bites a healthy person, the parasites are transmitted into their bloodstream.
C) Ascariasis
Answer:
Ascariasis - It is transmitted through food and water contaminated with eggs of the parasite.
D) Pneumonia
Answer:
Pneumonia - It transmits through droplet infection, i.e., through a sneeze, cough, sharing utensils, etc.
Ques 4. What measures would you take to prevent water-borne diseases?
Answer:
Waterborne diseases such as typhoid and cholera are prevented by:
Ques 5. Discuss with your teacher what 'a suitable gene' means in the context of DNA vaccines.
Answer:
A suitable gene is a unique segment of DNA that is implanted in the body to make certain proteins. These proteins protect the body against dangerous disease-producing organisms.
Ques 6. Name the primary and secondary lymphoid organs.
Answer:
Lymphoid organs help in making and activating immune cells:
Ques 7: The following are some well-known abbreviations which have been used in this chapter. Expand well-known abbreviations
a) MALT
Answer:
MALT- Mucosal Associated Lymphoid Tissue
b) CMI
Answer:
CMI - Cell Mediated Immunity
c) AIDSAnswer:
AIDS- Acquired Immune Deficiency Syndrome
d) NACOAnswer:
NACO- National AIDS Control Organisation
e) HIVAnswer:
HIV- Human Immunodeficiency Virus
Ques8: Differentiate the following and give examples of each:
a) Innate and acquired immunity
Answer:
| Innate Immunity | Acquired Immunity | 
| Present from birth and provides general protection. | Develops when the body is exposed to specific infections. | 
| Acts as the first line of defence | Acts as the second line of defence | 
| Passed down genetically. | Not inherited from parents. | 
Answer:
| Active Immunity | Passive Immunity | 
| The body produces its antibodies after infection or vaccination. | Antibodies are given from an external source (e.g., injection). | 
| Long-lasting protection. | Short-term protection. | 
| Takes time to develop. | Works immediately. | 
Answer:
The well-labelled diagram of an antibody molecule is as follows:

Ques 10. What are the various routes by which transmission of the human immunodeficiency virus takes place?
Answer:
HIV is transmitted in various ways:
Answer:
HIV causes a deficiency of the immune system in the following ways:
Ques 12. How is a cancerous cell different from a normal cell?
Answer:
Differences between cancerous cells and normal cells
| Cancerous Cells | Normal Cells | 
| Cancerous cells divide uncontrollably and may form tumours. | Normal cells grow and divide in a regulated manner. | 
| It can spread to other tissues and organs | Stay in one place and perform normal functions | 
Answer:
Metastasis is the condition in which cancer cells move from the primary location to other locations of the body through the blood or lymph. It is the terminal stage of cancer.
Answer:
Drug and alcohol abuse result in:
Answer:
Yes, peer pressure can result in drug or alcohol consumption. It can be prevented by:
Ques16. In your view, what motivates youngsters to turn to alcohol or drugs, and how can this be avoided?
Answer:
Teenagers can begin consuming alcohol or drugs because of:
Prevention is achieved through:
Answer:
After a person begins to take drugs or alcohol, it is hard to quit because:
NCERT Solutions for Class 12- Subject-wise
Below are a few steps that students can follow to solve the questions from this chapter easily.
Students first need to understand the difference between infectious and non-infectious diseases.
Different diseases like typhoid, pneumonia, malaria, and ascariasis should be studied in detail. Students can create flashcards using the Class 12 Biology Chapter 7 Human Health and Disease question answers.
The next step is to understand the concept of immunity, its types, antibodies, and the immune system. For a detailed explanation, students can use the Class 12 Biology Human Health and Disease question answer.
Students can prepare short notes by highlighting the symptoms and effects of different drugs, and how to control drug abuse.
Also, check the NCERT Books and the NCERT Syllabus here:
The Human Health and Disease chapter helps students understand the causes of diseases and the importance of immunity. Given below are some of the important questions from this chapter. For more such questions, students can refer to the NCERT Solutions for Class 12 Biology Chapter 7 Human Health and Disease. This improves their problem-solving skills and makes them familiar with the question pattern.
Question 1: Haemozoin is a
A. precursor of haemoglobin
B. The toxin released from Streptococcus-infected cells
C. The toxin released from Plasmodium-infected cells
D. The toxin released from Haemophilus-infected cells
Answer: The correct answer is option (C), the toxin released from Plasmodium-infected cells
Explanation:
A dangerous byproduct generated by the parasite Plasmodium in malaria disease is haemozoin, which is a by-product of the ingestion of haemoglobin by the parasitic red cell.
Question 2: Which of the following is not the causal organism for ringworm?
A. Microsporum
B. Trichophyton
C. Epidermophyton
D. Microsporum
Answer: The correct answer is option (D), Microsporum
Explanation:
Ringworm, a common fungal infection of the skin, is caused by dermatophytes belonging to genera such as Trichophyton, Microsporum, and Epidermophyton. Non-dermatophyte organisms, like bacteria or viruses, are not responsible for causing ringworm. Ringworm infections typically affect the skin, hair, and nails, presenting as red, itchy, circular rashes.
Question 3: A person with sickle cell anaemia is
A. more prone to malaria
B. more prone to typhoid
C. less prone to malaria
D. is less prone to typhoid
Answer: The correct answer is option (C), less prone to malaria
Explanation:
Patients suffering from sickle cell anaemia demonstrate a distinct kind of immunity against malaria due to the abnormally shaped RBCs. Since the parasite will find less favour in sickle-shaped RBCs, severe infection would occur less often. This protection is confirmed through multiple clinical research works, mainly from malaria-prone areas where this sickle cell trait has occurred as an intrinsic mechanism for defending against malaria.
Question 4: Antibodies present in colostrum, which protect the newborn from certain diseases, are of
A. IgG type
B. IgA type
C. IgD type
D. IgE type
Answer: The correct answer is option (B), IgA type
Explanation:
The antibodies present in colostrum, the first milk produced by mammals after birth, are primarily of the IgA (Immunoglobulin A) class. Colostrum is rich in these antibodies, which play a critical role in protecting the newborn from infections.
Question 5: Which of the following is not a lymphoid tissue?
A. Spleen
B. Tonsils
C. Pancreas
D. Thymus
Answer: The correct answer is option (C), Pancreas
Explanation:
The pancreas is not a lymphoid tissue. The pancreas is an exocrine and endocrine organ mainly functioning in digestion and the regulation of blood sugar levels. The spleen, tonsils, and thymus are all regarded as lymphoid tissues that have a function in the immune system. The lymphoid organs are responsible for the production and maturation of lymphocytes. These are considered critical in the initiation of immune responses.
NCERT Exemplar Class 12 Solutions
The chapter explains the significance of maintaining health and how various diseases affect living organisms.
Students understand the causes, symptoms, and prevention of common diseases like typhoid, pneumonia, malaria, ascariasis, and filariasis.
Through the Human Health and Disease Class 12 question answer, learners get explanations of the immune system, including innate and acquired immunity, and immunisation.
The chapter highlights serious conditions like AIDS and cancer, explaining their causes, effects, and control measures.
With the help of the Class 12 Biology Human Health and Disease question answer, students learn how drug and alcohol abuse impacts humans and society.
Concepts like allergy, autoimmunity, and immunodeficiency are discussed to make students aware of immune system disorders.
The chapter Human Health and Disease focuses on the human immune system, common disease, their symptoms, and their prevention. The solutions for this chapter build a strong understanding of how the human body fights against infections.
For better NEET preparation, students can explore some extra topics beyond the NCERT. The table below lists key areas to focus on. Along with this, students can refer to the NCERT Solutions for Class 12 Biology Chapter 7 Human Health and Disease to avoid confusion.
Below are the Chapter-wise solutions:
Frequently Asked Questions (FAQs)
The NCERT Solutions for Class 12 Biology Chapter 7 Human Health and Disease explain different diseases, such as bacterial, viral, protozoal, and fungal. A few of them are malaria, pneumonia, amoebiasis, typhoid, dengue, and HIV/AIDS.
AIDS results from the HIV virus, which affects the immune system. The symptoms include weight loss, fever, tiredness, recurring infections, and inflamed lymph nodes.
Interferons are proteins that are released from cells as a response to viral infections. They protect surrounding cells from the virus and improve the immune system's response.
The chapter Human Health and Disease explains two types of immunity:
Vaccines are made of weakened or dead disease-causing germs. When they are put into the body, they make the immune system produce antibodies. This makes the body able to recognise and attack the infection in the future.
The important topics covered in the NCERT Solutions for Class 12 Biology Chapter 7 Human Health and Disease are different types of diseases, immunity, vaccines, and the role of the immune system in fighting infections. It also discusses AIDS, cancer, drug abuse, and public health measures.
The immune system makes white blood cells and antibodies to fight and kill dangerous microorganisms. It also contains memory cells that enable it to recognise and combat the same infection if it re-enters the body.
On Question asked by student community
Hello,
Since you have passed 10th and 12th from Delhi and your residency is Delhi, but your domicile is UP, here’s how NEET counselling works:
1. Counselling Eligibility: For UP NEET counselling, your UP domicile makes you eligible, regardless of where your schooling was. You can participate in UP state counselling according to your NEET rank.
2. Delhi Counselling: For Delhi state quota, usually 10th/12th + residency matters. Since your school and residency are in Delhi, you might also be eligible for Delhi state quota, but it depends on specific state rules.
So, having a Delhi Aadhaar will not automatically reject you in UP counselling as long as you have a UP domicile certificate.
Hope you understand.
Hello,
You can access Free CBSE Mock tests from Careers360 app or website. You can get the mock test from this link : CBSE Class 12th Free Mock Tests
Hope it helps !
Yes, it is possible for a student who has done their 12th grade already to take upto 4 exams of their requirement. This is possible through the NIOS, NATIONAL INSTITUTE OF OPEN SCHOOLING. Get more info about the exam and the board through the following link.
For CBSE the PREVIOUS YEARS PAPERS can be accessed through the following link for the Concerned subjec by careers360.
Consequently Careers360 does also have a chapter wise scheme of PYQs, you can access the STUDY MATERIAL (PYQs.) from the following link -
https://school.careers360.com/boards/cbse/cbse-question-bank
Thankyou.
 
Hello,
Sorry, but JoSAA does not accept marks from two different boards for the same qualification during counselling. However, you can use your NIOS marks to meet the JEE Main/Advanced eligibility criteria if they are better than your CBSE marks. You can use your NIOS marks for the eligibility check, but when presenting your documents, you may be required to present both marksheets and the one with the higher marks for each subject will be considered.
I hope it will clear your query!!

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