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  1. >>Class 12
  2. >>Biology
  3. >>Human Health and Disease
Common Misconceptions
7 min read

Human Health And Disease

- Clear the fog of misconceptions and get a clarity of concepts.
1
We always define antigens are the 'foreign substances' that elicit immune response. Yes, it is true. But, we also have self-antigens that are present on some cells of our body. Surprised? Our body recognizes them as self-antigens and does not attack these.
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Assertion
Assertion: Our blood cells have antigens on them, but our immune system does not attack our blood cells
Reason
Reason: Our immune system recognizes the self-antigens of our body and does not attack them.
A
Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B
Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
C
Assertion is correct but Reason is incorrect
D
Both Assertion and Reason are incorrect
2
Many people often get confused between arthritis and rheumatoid arthritis. Are they same? Well, they are different. Arthritis is a disease wherein there is pain, stiffness in joints due to some injury or infection, whereas, rheumatoid arthritis is an autoimmune disease wherein the immune system of the body attacks the self-antigens of the body causing joint pain.
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Which of the following is an autoimmune disease
This question has multiple correct options
A
Arthritis
B
Erythroblastosis foetalis
C
Diabetes Type 1
D
Rheumatoid arthritis
E
Asthma
3
What comes to your mind when you hear the word 'antigen'? Is the answer a pathogen? Well, you are partly correct but the actual answer is that antigens are substances that are part of the pathogen or are present alone.
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The antigen present in pathogen is 
A
A specific protein involved in metabolism
B
Polysaccharide synthesised by it in the host
C
A specific protein or polysaccharide present on its coat
D
None of the above
4
A person suffering from AIDS was not allowed to enter a shopping complex because everyone feared that the others will get the infection. Do you think it's correct? No, AIDS is a non-infectious disease and can spread by the exchange of body fluids only.
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AIDS is caused by HIV. Among the following, which one is not a mode of transmission of HIV?
A
Transfusion of contaminated blood
B
Sharing the infected needles
C
Shaking hands with infected persons
D
Sexual contact with infected persons
5
Common understanding about malaria is, that, it is caused by mosquitoes. But, malaria is caused due to a protozoan that is transmitted by mosquitoes. Also, not by all mosquitoes, but, by a specific type of mosquito - the female Anopheles. When the female Anopheles mosquito carrying the malaria pathogen, bites a healthy person, he/she gets infected by the pathogens present in the saliva of the mosquito. The person then develops the symptoms of malaria.
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Mosquitoes are the vectors for malarial parasite?
A
True
B
False
6
How do you think antibodies act on foreign antigens to eliminate them from the body? Do they kill them? The answer is no. Antibodies only bind with antigens, capture them and activate the other cells of the immune system to respond and act on the antigens.
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What happens when antibodies bind to specific antigens?
A
Kill the pathogen that the antigen belongs to
B
Activate cytotoxic T cells
C
Acivate complement system
D
Both B and C
7
Medicines are also called drugs and some types of drugs like opiates (morphine) can give a feeling of pleasure when consumed. Sounds good, right? But, wait, these drugs are very much harmful if consumed in excessive amounts. These can be fatal.
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Drugs 
A
Do not pose any health threat
B
Impair physical and mental health
C
Causes family disputes
D
Both B and C