Explanation:
AIDS is caused by the destruction of CD-4 bearing T-cells and other cells by HIV, over a period of years. The final stage of this process is marked by a low level of helper T-cells and opportunistic diseases characteristic of a deficient cell-mediated immune response. Hence statement A is correct.
HIV is transmitted when there is transfer of blood from an infected person to a healthy person, through any means. Hence statement B is incorrect.
Drug addicts are more susceptible to HIV infection as they use syringes for drugs and the infected syringes may transfer HIV infection in them. Hence statement C is incorrect.
AIDS can't be cured. The time period between the infection of HIV and its effects on body, can be increased with the help of medicines but HIV can never be cured fully. Hence statement D is incorrect.
So, the correct answer is 'The causative HIV retrovirus enters helper T- lymphocytes thus reducing their numbers'.
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$I.$ mass of neoplastic cells
$II.$ cells that grow very rapidly and damaging the surrounding normal tissue
$III.$ cells that show the property of metastasis
Which of the statements given above are correct?
$II.$ Some animals are poisonous
$III.$ Monarch butterfly are distasteful
The above adaptations are against
This type represents