Free Biodiversity and Variety of Life MCQs with Answers

411. The virus envelope is known as:

• A. Capsid
• B. Virion
• C. Nucleoprotein
• D. Core

Explanation: The capsid is the protein coat that surrounds the genetic material (either DNA or RNA) of a virus. It protects the genetic material and helps the virus attach to and enter host cells. As it is outer covering in most viruses so it is the correct answer.

412. Viruses possess:

• A. Ribosomes to synthesize protein
• B. Organelle for its vital mechanism
• C. Either DNA or RNA
• D. None of these

Explanation: Viruses possess either DNA or RNA as their genetic material. This genetic material can be single-stranded or double-stranded, depending on the type of virus. The genetic material carries the instructions for the virus's replication and function.

413. The phenomenon of transcription in the HIV life cycle occurs in:

• A. Nucleus
• B. Cytoplasm
• C. Inside viral capsid
• D. None of these

Explanation: In the nucleus, Reverse transcription occurs, the viral RNA is reverse transcribed into DNA by the reverse transcriptase enzymeIntegration: The DNA is integrated into the DNA of the host cell by the integrase enzyme. Transcription: The integrated DNA is transcribed into RNA by the host cell's DNA polymerase.

414. Which one of the following is a double-stranded DNA virus?

• A. Poxvirus
• B. Parvovirus
• C. Reovirus
• D. Togavirus

Explanation: Pox viruses are a family of viruses that contain double-stranded DNA. This means that their genetic material is made up of two strands of DNA that are linked together.

415. Virus that affects the genital organs:

• A. HCV
• B. HSV
• C. HIV
• D. Poxvirus

Explanation: HSV (Harpes simplex virus) particularly HSV-2, is a virus that commonly affects the genital organs. It causes genital herpes, characterized by painful sores or blisters in the genital and anal areas.

416. Protein of HIV that helps in its fusion with T cells:

• A. gp31
• B. gp120
• C. gp141
• D. gp41

Explanation: gp41 is another viral envelope glycoprotein of HIV. After the initial binding of gp120 to the CD4 receptor. gp41 facilitates the fusion of the viral envelope with the host cell membrane, allowing the viral genome to enter the host cell.

417. _ is common among all viruses during their infection cycles:

• A. DNA replication in cytoplasm
• B. Translation in cytoplasm
• C. Transcription in nucleus
• D. Reverse transcription in cytoplasm

Explanation: Translation, the process of protein synthesis, generally occurs in the cytoplasm for both prokaryotic and eukaryntic cells, including viral infections. Viral proteins are commonly synthesized in the host cell cytoplasm using the cellular machinery.

418. Virus attacks and hijacks host's _ to make more virus.

• A. Mitochondria
• B. Nucleus
• C. Ribosomes
• D. Endoplasmic reticulum

Explanation: Viruses often hijack host cell ribosomes for protein synthesis. They use the host's ribosomal machinery to produce viral proteins, which are essential for the assembly of new virus particles.

419. What is the size of parvovirus?

• A. 200nm
• B. 30nm
• C. 20nm
• D. 100nm

Explanation: Parvoviruses are the smallest known animal viruses, measuring only 18-26 nanometers in diameter. They are non-enveloped viruses with an icosahedral capsid and contain a single-stranded DNA (ssDNA) genome. Because of their tiny size and simple structure, parvoviruses rely heavily on the host cell's machinery for replication. An example is the human parvovirus B19, which causes fifth disease in children.

420. Eukaryotic, multicellular, and consumers belong to _ kingdom.

• A. Monera
• B. Protista
• C. Fungi
• D. Animalia

Explanation: Kingdom Monera: It comprises unicellular, prokaryotic organisms, which can be heterotrophic or autotrophic, having no well-defined nucleus and no organelles.Kingdom Protista: Protists are eukaryotic, unicellular organisms They can be autotrophs or heterotrophs.Kingdom Fungi: Fungi can be single-celled or very complex multicellular organisms. All fungi are heterotrophic, which means that they get the energy they need to live from other organisms.They are eukaryotes.Kingdom Animalia: They are eukaryotic, multicellular, and heterotrophic.