Differentiate between bening tumour and malignant immunity
| Benign Tumour | Malignant Tumour |
|---|---|
| It is a non-cancerous tumour. | It is a cancerous tumour. |
| Benign tumour does not show metastasis and is non-invasive. | It shows metastasis and thus invades other body parts. |
| It stops growth after reaching a certain size. | Malignant tumour shows indefinite growth. |
| Limited adherence occurs amongst cells of benign tumour. | There is no adherence amongst cells. They tend to slip past one another. |
| It is less fatal to the body. | It is more fatal to the body. |
Do you consider passive smoking is more dangerous than active smoking? Why?
Passive smoking can be equally dangerous because it exposes the persons to the same harmful effect of smoke.
Passive or second hand smoking means being in the same room or place, where some one is smoking and getting exposed to smoke in the surrounding air.
Once inhaled, the smoke can trigger release of mucus in the bronchioles that blocks the airways. This induces coughing. But prolonged exposures can lead to bronchitis emphysema, respiratory tract infections and eventually lung cancer.
'Prevention is better than cure'. Comment.
Prevention is always better than cures because some diseases cause extensive damage to the body tissues or organs and have a
(i) Negative effect on their capacity to function.
(ii) Permanent or long term debilitating effect.
(iii) Negative mental and psychological effect.
(iv) Financial burden.
Prevention, therefore is easier and effective, than cure of a disease.
Explain any three preventive measures to control microbial infections.
Preventive measures to control microbial infection include
(i) Maintenance of personal and public hygiene by
(a) Proper cleanliness standards and practices.
(b) Proper disposal of waste.
(c) Periodic cleaning of water reservoirs, etc.
(ii) Control or elimination of vectors that transmit diseases by
(a) Checking water stagnation and garbage accumulation.
(b) Using disinfectants or biological methods to check their breeding and spread.
(iii) Proper immunisation by vaccination, wherever available to control or completely eradicate infectious diseases.
In the given flow diagram, the replication of retro virus in a host is shown. Observe and answer the following questions.
(a) Fill in (A) and (B)
(b) Why is the virus called retrovirus?
(c) Can the infected cell survive, while viruses are being replicated and released?
(b) The virus is called retro virus because it does not follow the central dogma of biology (DNA $\rightarrow$ RNA $\rightarrow$ Proteins).
Its genetic material is RNA that is transcribed to DNA using enzyme reverse transcriptase.
(c) Yes, the infected cell can survive, while viruses are being replicated and released.