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Factual Passage: The Way Human Body Defends

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The Way Human Body Defends

  1. The defence mechanism of human body is a gift of nature provided to human beings. The power of our body to fight against various disease-producing agents is known as defensive mechanism. This defensive mechanism depends upon various factors which can be categorised mainly into two types-common factors and special factors.
  2. Amongst the common factors, the most important is the health of human beings. We all know if we are having a good health, our body automatically remains protected against the diseases. For keeping good health one should have nutritious balanced diet. A balanced diet is that which contains carbohydrates, fat, proteins, vitamins in proportionate amount.
  3. The skin of our body saves us against many micro-organisms producing diseases, provided that it is intact. In case there are cuts or abrasions on it, the micro-organisms penetrate the body through those cuts and abrasions and can cause diseases. Therefore, a cut or an abrasion should never be left open. In case there is no bandage, etc. available, it may be covered by a clean cloth.
  4. Some bacteria are residing on and inside the human body. They are our friends and are useful for us. They do not cause any disease and by their presence they do not allow disease-causing organisms to settle on those places. For example, the micro-organisms, present in human saliva secrete a chemical which does not allow diphtheria causing bacteria to grow inside the oral cavity.
  5. The human body secretes a variety of fluids, which are killers for disease causing micro¬organisms. For example, gastric juice (acidic in nature) secreted by our intestinal tract kills all organisms which enter our body through food.
  6. There are a few automatic activities of our body known as "reflex phenomenon" which protect the body against many infections. This reflex phenomenon includes sneezing, coughing and vomiting. 
  7. Fever is one of the most important constituents of the defensive mechanism of our body. The organ which regulates the temperature of our body is known as hypothalamus and it is situated in the brain. When micro-organisms after entering the body release toxic products and these reach the brain through blood, the hypothalamus starts increasing the temperature of body the person gets fever. This fever is very useful for the human body because by the increase of temperature the micro-organisms which are the root cause of the problem get killed.
  8. We are living in an environment which is full of bacteria. Many of these bacteria can produce serious diseases, but all of us do not suffer from such diseases. It is due to a special power present in our body to fight these diseases. A part of this special power of our body is known as innate immunity. This is inherited by us. The other part of this special power is called acquired immunity. This we gain during our lifetime.
  9. In a nutshell, we can say since nature has provided us with defensive mechanism to fight against so many diseases, let us maintain it and rather increase it by the way of immunisation.

A. Answer the following questions by choosing the most appropriate option:
Q.1. One should have nutritious balanced diet because_______
(a) it has food items for various tastes
(b) it keeps one healthy
(c) it is recommended by a dietician
(d) it has all essential items

Correct Answer is option (b)
it keeps one healthy

Q.2. In order to check the micro-organisms penetration in the human body_______
(a) we must cover the whole body
(b) we must rub insect repelling oil
(c) we must use antiseptic solutions
(d) we should keep cuts and abrasions covered

Correct Answer is option (d)
we should keep cuts and abrasions covered

Q.3. We can increase our defensive mechanism by_______
(a) developing friendly bacteria
(b) checking infection through reflex phenomenon
(c) seeking proper immunisation
(d) suppressing fever in initial stages

Correct Answer is option (c)
seeking proper immunisation

Q.4. The defence mechanism of human body is important as_______
(a) it protects us from diseases
(b) it checks deterioration of body
(c) it saves us from depression
(d) it builds up the wear and tear

Correct Answer is option (a)
it protects us from diseases.

Q.5. Gastric juice secreted by our intestinal tract kills all extraneous organisms as_______
(a) it flows very fast
(b) it is acidic in nature
(c) it prevents their multiplication
(d) it is a natural stimulant

Correct Answer is option (b)
it is acidic in nature

Q.6. (d) suppressing fever in initial stages_______
(a) blood poisoning
(b) study of poisons
(c) harmful bacteria in plants/animals
(d) poisonous

Correct Answer is option (d)
poisonous


B. Answer the following questions in brief:
Q.7. How can micro-organism's penetration be checked in the human body?

Micro-organism penetration can be checked in human body by keeping our cuts or abrasions covered.

Q.8. How can we increase our defensive mechanism?

We can increase our defensive mechanism by seeking proper immunisation.

Q.9. Give the similar meanings.
(a) scraping or rubbing of (para 3)
(b) poisonous (para 7)

(a) Abrasions
(b) Toxic

Q.10. What is the role of gastric juice in human body?

Gastric juice is acidic in nature it kills all extraneous organisms.

Q.11. What do you mean by reflex phenomenon? How is it helpful for human body?

few automatic activities of our body are known as reflex phenomenon which protect the body against many infections.

The document Factual Passage: The Way Human Body Defends is a part of the Class 11 Course Class 11 English Grammar.
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FAQs on Factual Passage: The Way Human Body Defends

1. How does the immune system protect the human body from infections and diseases?
Ans. The immune system uses white blood cells, antibodies, and physical barriers like skin to defend against harmful pathogens and invading microorganisms. It identifies foreign substances, neutralizes threats, and creates immunity through various defence mechanisms that work continuously to keep the body healthy.
2. What are the main lines of defence in the human body's protection system?
Ans. The human body has three defence lines: the first line includes physical barriers such as skin and mucus membranes; the second involves inflammation and phagocytes that destroy pathogens; the third comprises antibodies and immune cells that target specific invaders. Together, these layers provide comprehensive protection against disease-causing agents.
3. What exactly are antibodies and how do they help fight off infections in Class 11 biology?
Ans. Antibodies are special proteins produced by white blood cells that recognize and bind to specific pathogens, marking them for destruction. These Y-shaped molecules neutralize toxins, prevent microorganisms from entering cells, and activate immune responses to eliminate threats effectively and prevent recurrent infections.
4. Why do some people get sick less often than others-is it related to immune system strength?
Ans. Immunity varies based on genetics, nutrition, sleep quality, and previous pathogen exposure. Individuals with stronger immune responses have more effective white blood cells and antibody production. Lifestyle factors, vaccination history, and overall health significantly influence how frequently a person contracts infections and recovers from illness.
5. What's the difference between innate immunity and adaptive immunity in defending the body?
Ans. Innate immunity provides immediate, non-specific defence through physical barriers, inflammation, and natural killer cells present from birth. Adaptive immunity develops slowly but offers targeted, long-lasting protection through antibodies and memory cells that recognize specific pathogens encountered previously, creating lasting resistance against future infections.
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