Question:
Which of the following viral symmetry is found in bacterial viruses?
Which of the following viral symmetry is found in bacterial viruses?
Show Hint
Visualizing the classic "lunar lander" shape of a T4 bacteriophage is very helpful:
- The geometric "head" is icosahedral.
- The tubular "tail" is helical.
- This combination of two different symmetries is called Binal symmetry.
- The geometric "head" is icosahedral.
- The tubular "tail" is helical.
- This combination of two different symmetries is called Binal symmetry.
Updated On: Aug 3, 2026
- Complex Binal (both Icosahedral head and helical body) symmetry
- Helical or Icosahedral symmetry but not both
- Helical symmetry
- Complex symmetry with unusual morphology
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Step 1: Understanding the Concept:
This question addresses viral structural biology, focusing specifically on the symmetry and morphology of bacterial viruses (bacteriophages).
Step 2: Detailed Explanation:
Viruses exhibit different types of capsid symmetry to enclose and protect their genomic material. The primary forms of viral symmetry include helical, icosahedral (cubic), complex, and binal.
- Binal Symmetry:
Binal (or binary) symmetry is a unique structural feature found primarily in many bacteriophages (such as the T-even phages: T2, T4, and T6).
These phages possess a structural combination of two different symmetries:
1. An icosahedral (cubic) head which encapsulates the double-stranded DNA genome.
2. A helical body/tail assembly that is involved in attachment and injection of the viral genome into the host bacterial cell.
Because the virion combines both icosahedral and helical symmetries within a single structure, it is described as having binal symmetry.
Let us evaluate the other options:
- Option (B) and (C): While some phages may have simple icosahedral or helical shapes alone, binal symmetry is the highly characteristic and distinct structural symmetry associated with tailed bacterial viruses.
- Option (D): Complex symmetry with unusual morphology applies to viruses like Poxviruses, which lack a clearly defined icosahedral or helical capsid.
Therefore, Complex Binal symmetry is the correct option representing bacteriophages.
Step 3: Final Answer:
The viral symmetry found in bacterial viruses is Complex Binal symmetry.
Therefore, the correct choice is Option (A).
This question addresses viral structural biology, focusing specifically on the symmetry and morphology of bacterial viruses (bacteriophages).
Step 2: Detailed Explanation:
Viruses exhibit different types of capsid symmetry to enclose and protect their genomic material. The primary forms of viral symmetry include helical, icosahedral (cubic), complex, and binal.
- Binal Symmetry:
Binal (or binary) symmetry is a unique structural feature found primarily in many bacteriophages (such as the T-even phages: T2, T4, and T6).
These phages possess a structural combination of two different symmetries:
1. An icosahedral (cubic) head which encapsulates the double-stranded DNA genome.
2. A helical body/tail assembly that is involved in attachment and injection of the viral genome into the host bacterial cell.
Because the virion combines both icosahedral and helical symmetries within a single structure, it is described as having binal symmetry.
Let us evaluate the other options:
- Option (B) and (C): While some phages may have simple icosahedral or helical shapes alone, binal symmetry is the highly characteristic and distinct structural symmetry associated with tailed bacterial viruses.
- Option (D): Complex symmetry with unusual morphology applies to viruses like Poxviruses, which lack a clearly defined icosahedral or helical capsid.
Therefore, Complex Binal symmetry is the correct option representing bacteriophages.
Step 3: Final Answer:
The viral symmetry found in bacterial viruses is Complex Binal symmetry.
Therefore, the correct choice is Option (A).
Was this answer helpful?
0
0
Top ICAR AIEEA Veterinary Science Questions
- In ox vallate papillae are
- Spiral colon is characteristic of
- Assertion (A) : Stratum lucidum is translucent layer present between stratum spinosum and stratum granulosum
Reasoning (R) : Stratum lucidum is translucent due to presence of eledin protein.
In light of the above statements, choose the correct answer from the options given below. - Statement (I): Keratinocytes contain melanin pigment in the form of melanosomes.
Statement (II): Melanin pigment is produced by keratinocytes with the help of Tyrosinase enzyme.
In light of the above statements, choose the most appropriate answer from the options given below. - Which of the following is true for mast cells?
(A). These cells are common in loose connective tissue.
(B). These cells take metachromatic stain.
(C). These cells are rich in histamine, heparin and proteases.
(D). These cells contain basophilic cytoplasmic granules.
Choose the correct answer from the options given below:
View More Questions
Top ICAR AIEEA Immunology Questions
- Read the following statements about immunoglobulin M (IgM)
(A) IgM is the initial antibody produced during immune response to a foreign pathogen.
(B) IgM is a pentamer joined by J-chain with 10 F(ab) fragments and 10 paratopes
(C) Very high IgM levels are found in a group of primary immunodeficiencies characterized by susceptibility to infections and malignancies
(D) IgM cross placeta from mother to fetus and thus protects newborn progeny from intrauterine infections
Choose the correct answers from the options given below: - Given below are two statements
Statement (I) : Phagocytosis is a cellular process for ingesting and eliminating particles, including foreign substances, microorganisms, and apoptotic cells.
Statement (II) : The process of phagocytosis involves several sequential steps, namely, Particle recognition, Particle ingestion, Phagosome formation, Phagolysosome formation and digestion
In light of the above statements, choose the most appropriate answer from the options given below. - Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : Allergy to penicillin is example of Type 1 hypersensitivity and may be sometimes with fatal outcome.
Reason (R) : Type 1 hypersensitivity is mediated by IgE and Mast cell which undergo degranulation leading to heavy release of histamine that cause vasodialation
In light of the above statements, choose the most appropriate answer from the options given below. - The broad functions of the complement system are mentioned below. Choose the set of correct statements
(A) Activation of complement cascade and thereby mediate inflammation
(B) Direct killing of target cells/microbes by lysis
(C) Do not bind with apoptotic cells and antigen antibody complex
(D) Opsonization (labeling) of pathogens and cells for clearance/destruction
Choose the correct answer from the options given below: - Process of antibody formation is a slow-acting, long-lasting, and more specific adaptive immune response. The adaptive immune response in B cells, Helper T cells and Cytotoxic T cells involve four phases mentioned below. Arrange these phases according to the order of occurence from first to last.
(A) Activation: Activation responses involve both changes in gene expression and in the initiation of cell division.
(B) Memory: Long-lived, pre-activated immune cells that wait for a subsequent infection are formed in the memory phase of the adaptive immune response.
(C) Encounter: Cells must first encounter antigens by binding specifically to them using specialized membrane proteins.
(D) Attack: The immune cells attack invading pathogens or infected cells.
Choose the correct answer from the options given below:
View More Questions
Top ICAR AIEEA Questions
- Which of the following statements is false?
- Which of the following is an example of an inventory?
- According to Adam Smith, productivity gains could be brought about through .
- The supply curve for an artificially scarce good is .
- Which of the following would not be considered an opportunity cost of paid employment?
View More Questions