NCERT Solutions for Class 12 Biology, Chapter 8 - Human Health and Disease

In this chapter, you will learn the diseases which can affect human beings, immunity, and other illnesses. The chapter provides a proper introduction to various diseases that tend to affect the health and the immunity of a person, from infectious diseases such as a common cold to diseases that tend to affect your immunity such as AIDS. This chapter also discusses how the consumption of substances such as alcohol and drugs tends to affect our health in general.

Let us take a look at the topics of Class 12 Biology Chapter 8 – Human Health and Disease:

8.1 Common Diseases in Humans

8.2 Immunity

8.3 AIDS

8.4 Cancer

8.5 Drugs and Alcohol Abuse

In this chapter, you will study about:

Section 8.1: In the first section of chapter 8, you will learn about the common diseases that can occur in human beings. The organisms that cause diseases in a human being are known as pathogens. Pathogens harm the body of its host by living inside or on them. The diseases caused by pathogens are typhoid, pneumonia, common cold, malaria, ascariasis, elephantiasis, and ringworms are covered in this section.

Section 8.2: In this section, the term Immunity is discussed. We, individuals, are exposed to a large number of infectious agents, but we are not affected by all of them. This is because our body is constantly fighting against such foreign agents. The ability of one’s body to combat against disease-causing organisms which are granted by the immune system is known as immunity. The two types of immunity are: Innate Immunity and Acquired immunity.

Innate immunity is discussed here along with the four types of barriers that consists of the innate immunity. Acquired immunity is explained in this Subsection of immunity.

In this section, you will also learn about Active and Passive Immunity. Active immunity is a slow process where antibodies are produced in the host body in order to fight the antigens that have entered the body. Passive immunity is when ready-made antibodies are given to the body directly in order to protect it from harmful foreign agents. Vaccination and Immunisation have been explained in this section of chapter 8 of Biology.

The section also discusses how Allergies can affect the body of the host by creating an exaggerated response to the immune system because of certain antigens which are present in the environment. Some of the common examples of allergens are pollens; animal dander, etc.

Here, autoimmunity of a human being has been discussed as well, and the damages caused to the body are known as autoimmune diseases.

Section 8.3: This section will educate you on AIDS, which is not a congenital disease. Individuals acquire it during their lifetime. The full form of AIDS stands for Acquired Immuno Deficiency Syndrome. HIV virus causes this syndrome and the ways to prevent AIDS are also given in this section.

Section 8.4: For this section, the most dreaded disease known to man – Cancer, has been explained. Cancer causes numerous deaths around the world. The causes of cancer, detection, diagnosis and treatment have also been explained thoroughly.

Section 8.5: In this section, you will study how drugs and alcohol can damage the body. The drugs which are commonly abused are opioids, coca alkaloids, and cannabinoids.

For further reference, you can download NCERT Class 12 Biology Human Health and Disease Pdf or refer to human health and disease class 12 NCERT available here at UrbanPro.