Free Biodiversity and Variety of Life MCQs with Answers

• A. Injecting DNA
• B. Replication
• C. Dissolve bacterial cell wall
• D. All of these

Explanation: The lysozyme released by bacteriophages plays a crucial role in the infection cycle.

• A. 1935
• B. 1930
• C. 1932
• D. 1920

Explanation: The tobacco mosaic virus (TMV) was first successfully crystallized in 1935 by the American biochemist Wendell Meredith Stanley.This work…

• A. Influenza virus
• B. Herpes virus
• C. T4 virus
• D. All of these

Explanation: The T4 bacteriophage is a complex virus with a highly specialized structure.

• A. Polio virus
• B. Tobacco mosaic virus
• C. Measles virus
• D. Retrovirus

Explanation: Tobacco Mosaic Virus fits the description you provided. Tobacco mosaic virus is an RNA virus that causes tobacco mosaic disease.

• A. A person may contract syphilis by sharing milk with one already suffering from the disease.
• B. Hemophilia is one of the STDs.
• C. Genital herpes and sickle cell anemia are both STDs.
• D. The chances of a 5-year-old boy contracting an STD are very little.

Explanation: STDs are primarily transmitted through sexual contact, so the likelihood of a 5-year-old boy contracting an STD is very low due to the…

• A. The common cold is a mild viral illness, while pneumonia is a serious infection that affects the lungs.
• B. The common cold mainly affects the digestive system, while pneumonia only affects the heart.
• C. The common cold is caused by bacteria, while pneumonia is always caused by viruses.
• D. The common cold is usually treated with antibiotics, while pneumonia never requires them.

Explanation: In conclusion, the main difference between the common cold and pneumonia is that the common cold is a mild viral infection of the upper…

• A. HIV can be transmitted through eating food together with an infected person.
• B. Drug addicts are least susceptible to infection.
• C. AIDS patients are being fully cured cent percent with proper care and nutrition.
• D. The causative HIV retrovirus enters helper T-lymphocytes, thus reducing their numbers.

Explanation: HIV is a retrovirus that infects helper T-lymphocytes (CD4⁺ cells), which are essential for coordinating the immune system.

• A. Mode of nutrition
• B. Mode of reproduction
• C. Complexity of behavior
• D. Number of chromosomes

Explanation: In Whittaker's five-kingdom system of classification, the main basis is mode of nutrition, which distinguishes autotrophs (plants)…

• A. Red blood cells
• B. Platelets
• C. T-Helper cells
• D. Neutrophils

Explanation: The major cells infected by HIV are CD4+ T lymphocytes, as the virus binds to CD4 receptors to gain entry and replicate.

• A. Transcription
• B. Translation
• C. Replication
• D. Reverse transcription

Explanation: In HIV, the enzyme reverse transcriptase is essential for converting single-stranded viral RNA into double-stranded DNA, a process known…

• A. Linnaeus
• B. Whittaker
• C. Theophrastus
• D. Aristotle

Explanation: The artificial system of classification was first introduced by Theophrastus, often called the Father of Botany.

• A. Caused by a virus
• B. Caused by a Gram positive bacterium
• C. Caused by a Gram negative bacterium
• D. Not an infectious disease

Explanation: The common cold is caused by some 100 types of rhinoviruses. It is one of the most common infectious diseases in humans.

• A. B and C
• B. C and D
• C. A and D
• D. A and B

Explanation: Among the given statements, A is correct because Ernst Mayr proposed the widely accepted biological species concept, which defines a…

• A. Both the genus name and species name begin with capital letters.
• B. The generic name always starts with a capital letter, while the species name starts with a small letter.
• C. The author's name should always be written in full (never abbreviated) after the scientific name.

Explanation: The correct option is C because the genus name begins with a capital letter and the species name with a lowercase letter.

• A. Species
• B. Order
• C. Class
• D. Family

Explanation: Among the given options, species is the correct answer because it is less general in character than genus.

• A. Species are the basic units of classification.
• B. Species are the highest units of classification.
• C. Species are imaginary units of classification.
• D. Species are optional units of classification.

Explanation: Species are a natural population or group of natural populations of individuals that are genetically distinct and reproductively isolated…

• A. Kingdom-Class-Phylum-Order-Family-Genus-Species
• B. Kingdom-Division-Class-Family-Order-Genus-Species
• C. Kingdom-Division-Class-Order-Family-Genus-Species
• D. Kingdom-Phylum-Order-Class-Family-Species-Genus

Explanation: According to biosystematics, to construct the hierarchy of classification, one or more species are grouped into a genus, one or more…

• A. Mononomial
• B. Trinomial
• C. Binomial
• D. Polynomial

Explanation: Binomial nomenclature of scientific naming was first given by C. Linnaeus (1735) in his book Systema Naturae and later in "Species…

• A. Tuberculosis
• B. Cancer
• C. Poliomyelitis
• D. Aging

Explanation: Cancer may be curable in the next two decades. The completion of the human genome is causing profound changes in the thinking and…

• A. Vector
• B. Capsid
• C. Plasmid
• D. Genome

Explanation: A capsid is a protective protein shell made up of subunits called capsomeres, which are arranged in highly specific patterns that…