NCERT Questions for Class 12 Biology Chapter 7 – Human Health and Disease

Important Questions with Solutions of Class 12 Biology Chapter 7 – Human Health and Disease

1) How will the immune system be affected by removing the thymus gland from the human body?

Ans – The manufacturing & the evolution of T-lymphocytes is done by the thymus gland. By removing the thymus gland from the body, the human immune system becomes weak.

2) Distinguish between two different types of tumors.

Ans – The difference between the two different types of tumors is:

BENIGN TUMOR	MALIGNANT TUMOR
The location of the tumor is the only place it sticks to.	Affects the location of the tumor & the tissue surrounding the area and spreads all over the body.
Does not do any such harm.	Does harm.
The tumor develops slowly.	The tumor develops rapidly.
Damage caused is a controllable amount.	Damage caused is unlimited.

3) Define allergies along with them causing inflammatory responses inside the human body.

Ans – The substance resulting in the hypersensitive reaction of the immune system with contact with dust & pollen grains is called allergies. No such allergy is caused by a single contact with the allergens. With frequent exposure to the allergens, it mixes with the IgE on the mast cell resulting in the bursting of the cells and Histamines secreted, leading to the inflammatory response. Therefore, allergens are weak antigens.

4) Explain autoimmune diseases with examples.

Ans – The disease in which the immune system is badly affected, destroying the healthy cells is known as autoimmune disease. It is the separation of the healthy cells from the cells affected by the foreign organisms and self-cells. Self-antigen and elicit immunity are the first two affected by disrupting the immune system. Examples: Rheumatoid arthritis and myasthenia gravis.

5) Define Cannabinoids & name the plant from where it is obtained. Which body part is harmed due to the consumption of this?

Ans – With its presence in cannabis and interaction with Cannabinoid receptors, Cannabinoids are a gathering of naturally occurring chemicals.

The plant named Cannabis sativa and its inflorescence is where Cannabinoids are derived from.

The cardiovascular system is the main body part harmed during this consumption.

6) Elaborate on the steps followed by the humoral immune system once the body gets infected.

Ans – The humoral immune response is the immunity preparing antibodies to attack the microbes. Every specific antigen has been recognized by the receptors located on the surface of the B-cell. This B-cell when exposed to antigens results in proliferation. It forms a massive stimulating clone cell and is followed by huge B-lymphocytes. It gets converted into smaller antibody-producing cells, i.e. plasma cells. Antibodies formed by this procedure will enhance the initial proliferation by reacting with their antigenic determinant. Antibodies binding to the antigen results in the digestion of the antigen-antibody complex by the phagocytic cells. Some plasma cells change into memory cells if plasma cells are exposed to the same antigen.

7) Define vaccination. Explain the type of immunity secured by the vaccination.

Ans – Vaccination is the process of securing immunity in the body with vaccination. A weakened pathogen is pushed through vaccination against a particular pathogen that helps to create further antibodies. The pathogenic agent also might get neutralized by producing antibodies against these antigens. With massive antibodies and generation of memory B & T– cells, the vaccine reacts as the pathogens get its recognition.

It provides Active immunity.

Although, in extreme cases when the patient is infected with some deadly microbe, they are directly injected with the immunity, this quick immunization is known as Passive immunization.

8) Define “Outbreeding” and explain its different methods.

Ans – The process of breed between random male animals & random female animals is called Outbreeding. Implement the below options to perform it:

1. OUT CROSS – It is the breeding of the animals within the same breed for 4-6 generations (therefore no common ancestors) of pedigree. It’s best for animals with a low growth rate of beef cattle, lower milk production, etc.
2. CROSS-BREEDING – Mating between the superior male and superior female of diverse breeds, thus as a combination of qualities of two different breeds assists for commercial production. For example: the mating of Bikaneri ewes and Marino rams will reproduce a new breed of ship called Hisardale.
3. INTERSPECIFIC HYBRIDISATION – In this mating/breeding occurs between the different male and female species therefore the offspring is the best feature of the two. For example: Donkey and female horses reproduced the mule.

Class 12 Biology Chapter 7 – Human Health and Disease Key Concepts

Class 12 Biology, Chapter 7, launches the student right into the intricate balancing act between human health and disease. The need to understand the mechanisms underlying our well-being lies at the root of staying healthy and withstanding or fighting diseases that may set us back in life.

Factors Affecting Health

Our health can get influenced by a variety of factors, including our genetics, personal choices made while living our lifestyle, environmental exposures, and social determinants. Class 12 Biology Chapter 7 deals with factors that determine our health and wellbeing. The more we understand what those influences are, the better we can protect our health, decreasing the possibility of illness.

Knowing Disease

Diseases are changes resulting in abnormal physiological or psychological activities of the human body. Chapter 7 describes the kinds of diseases, their causes or agents, symptoms, and treatments. The more one is aware of disease processes, the better he or she can detect signs and symptoms of disease and receive appropriate medical care.

Preventive Measures

The old adage says that prevention is better than cure; this applies very aptly to the context of health. Against contracting disease and ensuring wellness of health, there are various preventive measures that can be taken, which shall be elaborated on in Chapter 7. Students will learn how to protect themselves from illness through proper nutrition, regular exercise, vaccination, and hygiene measures.