NCERT Solutions Class 12 Biology Chapter 8
Biology is vital because it enables us to comprehend how living things function and interact on various levels. The word “biology” come from the Greek words “bios” (life) and “logos” (word) (meaning “study”). Other science oriented professions such as medicine, nursing and allied health, pharmacy and pharmacology, dentistry, and veterinary medicine also come under biology.
NCERT Class 12 Biology Chapter 8 is about Human Health and Disease. The effects of medicines are studied during medicine degrees. Human Health and Disease is a major subject in the NCERT syllabus for Class 12. This chapter covers important topics such as different diseases in humans, types of immunity, Cancer, HIV and AIDS, and many more.
Biology is an intricate subject and many students find it challenging. Students can easily understand all the concepts through our NCERT Solutions Class 12 Biology Chapter 8. This encourages the students to master the topic and increases their confidence to achieve a high grade Extramarks introduces Chapter 8 Biology Class 12 NCERT Solutions to make this challenging subject easier.
NCERT Solutions Class 12 Biology Chapter 8 students can easily understand all the concepts . This encourages the students to master the topic and increases their confidence to achieve a high grade
In addition to Class 12 Biology Chapter 8 NCERT Solutions, students can use the Extramarks website to access several other study resources. For example, NCERT books, CBSE revision notes, CBSE sample papers, CBSE previous year question papers, and other materials are available for students.
Key Topics Covered in NCERT Solutions Class 12 Biology Chapter 8
Listed below are the key topics that are covered in NCERT Solutions for Class 12 Biology Chapter 8- Human Health and Disease:
Introduction to Health
NCERT Solutions Class 12 Biology Chapter 8 explains the concept of health and the factors affecting it. In layman’s language , health is the absence of all illnesses and infections. However, the World Health Organisation (WHO) defines health as more than just the absence of disease or sickness. It refers to a state of physical, mental, and social well-being that is active and energetic. Individuals can maintain excellent health by eating a well-balanced diet and exercising regularly. Several elements influence one’s health, including:
- A diet that is not well balanced.
- Disorders of the Gene.
- Anxiety and stress.
- Pathogen infection is when a person is infected with a pathogen.
- Consumption of harmful and unsanitary foods.
- Exercise and other physical activities are lacking.
A healthy and balanced diet, decent personal cleanliness, frequent exercise and other physical activity are essential components. In addition, everyone should be informed of the various illnesses and their consequences and preventive measures to manage their health.
Common Diseases in Humans
NCERT Solutions Class 12 Biology Chapter 8 explains disease as an undesirable condition that affects a living entity that is otherwise healthy. Infectious and non-infectious diseases are the two broad categories:
Infectious Disease: Pathogens such as bacteria, viruses, fungi, and parasites cause these diseases, which may be readily spread from one person to another, making them infectious or contagious. Infectious illnesses include the common cold, tuberculosis, influenza, ringworm, and malaria.
Non-Infectious Disease: Non-infectious diseases, also known as non-communicable diseases, cannot be transmitted from one person to another. Genetic abnormalities, bad diets, a lack of physical exercise, and a few environmental variables can all contribute to these diseases.
Some common Diseases in Humans:
- Salmonella typhi, a pathogenic bacteria, is known to cause typhoid in humans. A widal test can be used to confirm this fever.
- Streptococcus pneumoniae and Hemophilus influenza are the bacteria that cause pneumonia.
- Rhinovirus is a virus that causes one of the most common viral diseases in humans, the common cold.
- Plasmodium, a tiny protozoan, causes malaria. Entamoeba histolytica is another protozoan that causes amoebiasis (amoebic dysentery).
- The intestinal parasite Ascaris causes ascariasis.
- Filariasis or elephantiasis is caused by the filarial worm Wuchereria.
Immunity
Immunity is the body’s capacity to protect, defend, and fight against infections such as bacteria, viruses, and other foreign bodies and poisonous chemicals. Immunity may be divided into two categories as explained by NCERT Solutions Class 12 Biology Chapter 8:
Innate Immunity
Innate immunity is that has been present since birth and is non-specific. Pathogen penetration is limited by this immunity, which employs several barriers- psychological barrier, physical barrier, cytokine barrier and cellular barrier.
Acquired Immunity
Acquired immunity is pathogen-specific and develops over one’s life. Active immunity, which is acquired naturally or secondary or anamnestic response, occurs when a person suffers an illness or sickness due to their exposure to a pathogen, and their body becomes immune to the disease as a result of the formation of the immune response in the body.
Active and Passive Immunity
Active immunity is when the host is exposed to antigens, the host creates antibodies in the form of dead or live microorganisms. It’s a time-consuming process that takes a long time to complete.
On the other hand, passive immunity is a type of immunity in which the body is supplied with ready-made antibodies to defend it from outside invaders.
Allergies
Allergic illnesses are another name for allergies. They are a group of diseases induced by the immune system’s hypersensitivity to various normally innocuous chemicals in the environment. For example, allergies develop when the immune system reacts to a foreign substance such as pollen, bee venom, or a meal that causes no reaction in most people.
Sneezing, runny nose, watery eyes, and trouble breathing are all symptoms of allergic reaction, as stated by NCERT Solutions Class 12 Biology Chapter 8.
Immune System in the Body
Lymphoid organs, tissues, cells, and antibodies make up this system. The immune system works in the following way:
- First, it aids in the distinction between self and non-self.
- Second, it defends the body against foreign or non-self antigens.
- Third, it is based on the development of memory cells and reacts to previously present antigens.
- Fourth, it’s a component of allergic responses.
- Fourth, it is critical in the treatment of auto-immune illnesses.
- Finally, it’s crucial in the case of organ transplantation and graft rejection.
AIDS
The Human Immunodeficiency Virus (HIV) causes Acquired Immunodeficiency Syndrome, impairing the body’s capacity to fight infection. The virus is spread by coming into contact with contaminated blood, sperm, or vaginal secretions. AIDS was first detected in 1981, and it has spread over the world in the subsequent twenty-five years, killing over 25 million people.
- Fever, tiredness, and a sore throat are flu-like symptoms that develop within a few weeks of infection.
- After that, the illness goes asymptomatic until it develops into AIDS. AIDS symptoms include weight loss, fever or night sweats, exhaustion, and recurring infections.
- Although there is currently no cure for AIDS, antiretroviral therapy can help decrease the disease’s progression and avoid secondary infections and consequences.
Prevention and Control
- Making blood transfusions HIV-safe.
- To avoid using the same needles that have already been used.
- Condoms are given away for free.
- Keeping drug misuse under control.
- Promoting the use of safe sex.
- Promoting HIV testing in vulnerable communities regularly.
- The role of society in stopping the disease’s spread.
- Heartfelt sympathy for the people living with HIV/AIDS.
- To raise public awareness about AIDS to prevent it from spreading.
- To prevent the spread of this disease, society and medical facilities must work together. In addition, to avoid the transmission of HIV to other people, it is necessary to disclose one’s HIV status.
The concept of HIV-AIDS and its precautions have been explained by NCERT Solutions Class 12 Biology Chapter 8 in the above section. To obtain notes of the same, refer to the Extramarks website.
Cancer
In our bodies, cell development is tightly regulated and coordinated. Still, when these systems fail, the differentiation of cells becomes uncontrollable, resulting in the creation of cancer cells and uncontrollable growth. These malignant cells will continue to divide, resulting in the creation of uncontrolled growth cells known as tumours.
Types of Tumours
There are two types of tumours, as explained by NCERT Solutions Class 12 Biology Chapter 8:
- The term “benign tumour” refers to a tumour that has been differentiated and encapsulated. Benign tumours develop at a slower rate, and they usually stay localised and do not migrate to other regions of the body, resulting in less harm.
- The “malignant tumours”, on the other hand are a mass of proliferating cells called neoplastic or tumour cells. They form when cells proliferate out of control. The condition can become life-threatening if the cells continue to develop and spread. During metastasis, malignant tumours can develop swiftly and move to other areas of the body.
Drugs and Alcohol Abuse
The abuse of drugs, which are chemical compounds not prescribed by doctors and consumed in large doses, frequently results in the impairment of a person’s physical and psychological functioning, leading to drug addiction.
When a person achieves reproductive maturity, they enter adolescence. This is a period between childhood and adulthood.. Various physiological and psychological changes occur throughout this time, resulting in the individual’s emotional and behavioural development. Individuals are exceptionally emotional and vulnerable during this time. This may sometimes lead to Alcohol abuse.
Prevention and Control methods explained by NCERT Solutions Class 12 Biology Chapter 8:
- But, first, avoid putting yourself under undue peer pressure.
- Counselling and education
- Seeking assistance from family and friends.
- On the lookout for warning indicators.
- Looking for professional and medical assistance.
NCERT Solutions Class 12 Biology Chapter 8 Exercise and Solutions
Extramarks Students can access previous years question papers, revision notes, extra problems, and more on the Extramarks website. Click on the links below to view NCERT Solutions Class 12 Biology Chapter 8:
Class 12 Science Biology 8: Very Short Answer Type Questions
Class 12 Science Biology 8: Short Answer Type Questions
Class 12 Science Biology 8: Long Answer Type Questions
Students may access NCERT Solutions Class 12 Biology Chapter 8 and other chapters by clicking here. In addition, students can also explore NCERT Solutions for other classes given below.
- NCERT Solutions Class 1
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By getting access to NCERT Solutions Class 12 Biology Chapter 8, students can easily understand all the concepts of Reproduction and its different concepts.
Key Features of NCERT Solutions Class 12 Biology Chapter 8
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