Given below is the list of viruses in Column X and their receptors in human host cells in Column Y. Column X Viruses Column Y Receptors A. Influenza A i. CD21 B. SARS coronavirus ii. Sialic acid C. Poliovirus iii. ACE 2 D. HIV iv. CD4 E. Epstein-Barr Virus v. CD155 Which one of the following options gives all correct matches between Column X and Column Y?
A - ii; B - iii; C - v; D - iv; E - i
Virus Receptors on Human Host Cells
Viruses are microscopic pathogens that need to infect host cells to replicate. To enter a human host cell, a virus typically binds to a specific molecule on the cell surface called a receptor. This binding is highly specific, much like a key fitting into a lock, and determines which cell types a particular virus can infect.
The question asks us to match specific viruses from Column X with the human host cell receptors they use for entry, listed in Column Y. Based on known virology, different viruses utilize different protein or carbohydrate molecules on host cells.
Let's match the viruses with their corresponding receptors:
| Column X: Viruses | Column Y: Receptors in Human Host Cells | Match |
|---|---|---|
| A. Influenza A | ii. Sialic acid | A - ii |
| B. SARS coronavirus | iii. ACE 2 (Angiotensin-converting enzyme 2) | B - iii |
| C. Poliovirus | v. CD155 (PVR - Poliovirus receptor) | C - v |
| D. HIV (Human Immunodeficiency Virus) | iv. CD4 (Cluster of differentiation 4) and co-receptors (CCR5 or CXCR4) | D - iv |
| E. Epstein-Barr Virus | i. CD21 (Complement receptor 2) | E - i |
Reviewing the specific matches:
- Influenza A viruses primarily bind to Sialic acid residues present on the surface of cells in the respiratory tract.
- The SARS coronavirus, including SARS-CoV-1 and SARS-CoV-2 (causing COVID-19), uses the ACE 2 receptor for entry into human cells, particularly in the lungs, heart, and intestines.
- Poliovirus, the causative agent of polio, enters cells by binding to the Poliovirus receptor, also known as CD155.
- The HIV virus infects immune cells, primarily T helper cells, by binding to the CD4 receptor and a co-receptor (either CCR5 or CXCR4). The primary binding is to CD4.
- The Epstein-Barr Virus (EBV), which causes infectious mononucleosis, enters B lymphocytes by binding to the CD21 receptor.
Therefore, the correct matching option is A - ii, B - iii, C - v, D - iv, E - i.
Important Questions from Host parasite interaction
In what respect does the genome of slow-acting retroviruses differ from those of transducing viruses?
Listeria is a food-borne pathogen that causes mild gastro-intestinal symptoms. To move from one host-cell to another, it polymerizes actin into a comet tail like structure. Listeria can assemble host-cell actin at its rear end because:
A. Listeria has on its surface a protein called ActA
B. Listeria can activate Arp 2/3 complex
C. Listeria has on its surface γ-tubulin
D. Listeria has on its surface myosin II motor
Which one of the following options represents all correct statements?
Which one of the following plant pathogens has largest genome size?
Pathogens continuously evolve strategies to evade host immune responses. For each of the following evasion strategies (listed in column X) match the pathogen (listed in column Y) which adopts it:
Choose the correct matchColumn X Column Y A Changing the antigen expressed on their surface (i) Influenza virus B Increasing phagocytic activity of macrophage (ii) Neisseria C Developing resistance to
complement-mediated lysis(iii) Gram +ve
bacteriaD Secreting proteases to inactivate antibodies (iv) No bacteria
E Allowing point mutations in
surface epitopes resulting in
antigenic driftPR proteins play important role during plant-pathogen interactions. Column X represents some of the PR family proteins and column Y represents their main properties.
The correct match of column X with the property in column Y isColumn X Column Y A PR - 2 (i) Defensin B PR - 5 (ii) Thaumatin-like C PR - 12 (iii) Lipid transfer protein D PR - 14 (iv) β-1, 3 - glucanase
