Tag: zoology
Questions Related to zoology
AIDS cannot be transmitted by
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Sexual contact
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Hugs
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Breast feeding
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Blood transfusion
AIDS is a viral disease transmitted through certain body fluids such as semen, saliva, blood, the breast milk of an AIDS infected person by sexual contact, breastfeeding from HIV-infected mother can transmit AIDS to the baby and by blood transfusion. During hug, no body fluid is entered into the body from one person to another. Thus, the correct answer is option B.
Which of the following diseases spread through infected needles or by blood transfusion?
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Measles
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Mumps
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AIDS
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Kalazar
AIDS (Acquired immunodeficiency syndrome) is an infection which is caused by Human immunodeficiency virus (HIV). The causative agent of the disease is a virus and so the disease can spread from one person to the other by sexual contact. The disease also spreads through the use of the infected needles, syringes and blood transfusion from the infected person.
The Human Immunodeficiency Virus causes AIDS by
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depleting $CD _{4}^{+}$ T-helper lymphocytes
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increasing $CD _{4}^{+}$ T-helper lymphocytes
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depleting $CD _{4}^{+}$ T- helper erythrocytes
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increasing $CD _{4}^{+}$ T- helper erythrocytes
HIV causes AIDS by destroying or depleting the number of CD4+ cells or they may functionally impair the cells. This reduces the ability of the immune system to fight against diseases. So, the correct option is 'depleting CD+4 T-helper lymphocytes'.
HIV selectively targets.
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B - memory cells
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B - effector cells
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T - cytotoxic cells
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T - helper cells
HIV multiplies in macrophages and then new viruses targets T - helper cells which makes the infected person immuno - deficient . So the correct option is "T- helper cells"
Which of the following cells are infected in case of HIV infection?
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$T _H$-cells
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Macrophages
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$CD^+ _4$ cells
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All of the above
HIV is a human immunodeficiency virus. When a person is infected by the HIV, it causes HIV infection. It affects the immune system of the body. It infects cells of the human immune system, such as helper T (T$ _H$) cells (CD$ _{4+}$ T cells), macrophages and dendritic cells. Due to this, it is difficult for the body to fight off other infections.
Consider the following statements and select the option which correctly identifies true(T) and false(F).
AIDS virus kills WBC and reduces immunity of the body.
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True
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False
AIDS virus destroys the immune system by attacking white blood cells called CD4 cells. HIV gets inside the CD4 cells and make copies of itself and then kills the CD4 cell. The new HIV copies find other CD4 cells to attack them. Thus, it destroys the immune cells, therefore reduces immunity.
Identify the incorrect statement about the HIV virus.
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The viral nucleotides contain ribose.
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HIV contains uracil, not thymine.
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HIV infection begins with the entrance of the virus into the host when the gp 120 and gp 41 function to pull the virus across the plasma membrane.
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HIV makes the host cell produce reverse transcriptase.
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Immunization against HIV has proven difficult because the virus mutates so rapidly.
HIV (Human Immunodeficiency Virus) has a viral envelope, matrix proteins and core. The viral core consists of two single strands of RNA for its genome. The RNA genome consists of ribonucleotides (ribose + nitrogenous bases + phosphate) wherein thymine is replaced by uracil. The quick mutation rate of RNA genome makes it difficult to have a vaccine against it. The viral coat has trimeric glycoprotein gp120 which contacts CD4 terminal domain of the T4 cell. This contact leads to activation of gp120 followed by contact with chemokines receptor CCR5, a multipass membrane protein. The result is activated gp41 which in turn cleaves gp120. The terminal domain of gp41 interacts with the target cell and fuses with the T cell membrane to facilitate entry of virus with capsid into the cell. RNA retroviruses have reverse transcriptase enzyme that synthesizes a DNA copy (cDNA) of viral RNA. Thus, the correct answer is option D.
The HIV virus compromises the immune system mainly by infecting:
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Cytotoxic 1-cells
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Helper T-cells
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Suppressor T-cells
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Plasma cells
HIV attacks and kills immune systems cells known as Helper T cells. Without Helper T cells many other immune system cells cannot work properly, including B cells that make antibodies
HIV infects all of the following except
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Monocytes
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T-cells
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Macrophages
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B-cells
HIV is a virus that targets and alters the immune system, increasing the risk and impact of other infections and diseases. It damages the immune system and infects macrophages, T- cells etc.
The human immuno deficiency virus (HIV) is a living entity because it can
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Undergoes reproduction in the host cell
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Disturb host cell respiration
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Excrete in human serum
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Move from one cell to another