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Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

AIDS cannot be transmitted by

  1. Sexual contact

  2. Hugs

  3. Breast feeding

  4. Blood transfusion
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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.

Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

Which of the following diseases spread through infected needles or by blood transfusion?

  1. Measles

  2. Mumps

  3. AIDS

  4. Kalazar
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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.

Thus, the correct answer is option C. 

Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

The Human Immunodeficiency Virus causes AIDS by

  1. depleting $CD _{4}^{+}$ T-helper lymphocytes
  2. increasing $CD _{4}^{+}$ T-helper lymphocytes
  3. depleting $CD _{4}^{+}$ T- helper erythrocytes
  4. increasing $CD _{4}^{+}$ T- helper erythrocytes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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'.

Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

Which of the following cells are infected in case of HIV infection?

  1. $T _H$-cells

  2. Macrophages
  3. $CD^+ _4$ cells

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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. 

Thus, the correct answer is 'All of the above.'

Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

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.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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. 

So, the given statement is true.

Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

Identify the incorrect statement about the HIV virus.

  1. The viral nucleotides contain ribose.

  2. HIV contains uracil, not thymine.

  3. 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.

  4. HIV makes the host cell produce reverse transcriptase.

  5. Immunization against HIV has proven difficult because the virus mutates so rapidly.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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.

Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

The HIV virus compromises the immune system mainly by infecting:

  1. Cytotoxic 1-cells

  2. Helper T-cells

  3. Suppressor T-cells

  4. Plasma cells
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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 

So, the correct option is 'Helper T cells'.

Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

The human immuno deficiency virus (HIV) is a living entity because it can

  1. Undergoes reproduction in the host cell

  2. Disturb host cell respiration

  3. Excrete in human serum

  4. Move from one cell to another
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
HIV infects a type of white blood cell in the body’s immune system called a T-helper cell (also called a $CD _4$ cell). These vital cells keep us healthy by fighting off infections and diseases. HIV cannot grow or reproduce on its own. Instead, the virus attaches itself to a T-helper cell and fuses with it. It then takes control of the cell’s DNA, replicates itself inside the cell, and finally releases more HIV into the blood – continuing the multiplication process. This is the HIV life cycle. 
So the correct option is 'Undergoes reproduction in the host cell'