MDCAT Biodiversity (Variety of Life ) MCQs

1. What is the primary focus of biodiversity?

A) The study of human cultures
B) The variety of life forms in a given ecosystem
C) The classification of viruses
D) The structure of prokaryotic cells

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2. Which of the following levels of biological classification is the broadest?

A) Species
B) Genus
C) Family
D) Domain

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3. The scientific classification system was developed by:

A) Charles Darwin
B) Carl Linnaeus
C) Gregor Mendel
D) Louis Pasteur

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4. What is the main structural component of viral capsids?

A) Lipids
B) Carbohydrates
C) Proteins
D) Nucleic acids

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5. Viruses are classified primarily based on:

A) Their size
B) The type of nucleic acid they contain
C) Their shape
D) Their mode of transmission

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6. Which of the following is NOT a characteristic of viruses?

A) They can reproduce independently
B) They contain genetic material
C) They are composed of proteins and nucleic acids
D) They require a host cell to replicate

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7. What type of virus is HIV?

A) RNA virus
B) DNA virus
C) Retrovirus
D) Bacteriophage

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8. The term “biodiversity hotspot” refers to:

A) Areas with high levels of species endemism and threat
B) Locations with diverse human cultures
C) Regions with many types of viruses
D) Places where biodiversity is declining rapidly

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9. The structure of HIV consists of:

A) Single-stranded RNA and a protein coat
B) Double-stranded DNA and a lipid envelope
C) Circular RNA and no protein coat
D) Double-stranded RNA and a rigid structure

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10. The classification system that includes the hierarchical levels of organization is known as:

A) Phylogenetics
B) Taxonomy
C) Ecology
D) Systematics

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11. In the context of viral diseases, the term “vector” refers to:

A) The host organism
B) An organism that transmits the virus
C) The virus itself
D) The method of infection

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12. Which of the following viruses is primarily responsible for AIDS?

A) HPV
B) HCV
C) HIV
D) HSV

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13. The most effective way to prevent the spread of HIV is through:

A) Vaccination
B) Safe sex practices
C) Antibiotics
D) Antiviral medications

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14. What is the primary target cell for HIV in the human body?

A) Red blood cells
B) Neurons
C) CD4+ T cells
D) Epithelial cells

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15. The outer layer of a virus that protects its genetic material is called:

A) Capsid
B) Envelope
C) Nucleoid
D) Peptidoglycan

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16. Which of the following diseases is caused by a virus?

A) Tuberculosis
B) Diabetes
C) Influenza
D) Malaria

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17. The term “endemic” refers to:

A) Species that are extinct
B) Species that are found only in a specific geographical area
C) Species that migrate seasonally
D) Species that are invasive

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18. What does the term “species richness” refer to?

A) The total number of individuals in a community
B) The number of different species in a given area
C) The genetic diversity within a species
D) The variety of ecosystems in a region

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19. Which of the following is an example of a viral vector used in gene therapy?

A) Adenovirus
B) Plasmid
C) Bacteriophage
D) Yeast

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20. The first recognized case of AIDS was reported in:

A) 1981
B) 1975
C) 1990
D) 1985

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21. The classification of living organisms into three domains includes:

A) Eukarya, Bacteria, and Archaea
B) Eukarya, Fungi, and Protista
C) Plantae, Animalia, and Fungi
D) Bacteria, Algae, and Protozoa

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22. Which of the following structures is unique to prokaryotic cells?

A) Nucleus
B) Ribosomes
C) Cell wall
D) Mitochondria

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23. What is a common mode of transmission for HIV?

A) Airborne particles
B) Contaminated water
C) Sexual contact
D) Insect bites

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24. Which of the following viral diseases is characterized by a rash and flu-like symptoms?

A) Chickenpox
B) Measles
C) Influenza
D) Ebola

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25. Which of the following is NOT a viral disease?

A) AIDS
B) Tuberculosis
C) Herpes
D) Hepatitis

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26. The HIV virus is primarily transmitted through:

A) Saliva
B) Blood
C) Urine
D) Feces

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27. The term “biodiversity” encompasses:

A) Genetic diversity
B) Species diversity
C) Ecosystem diversity
D) All of the above

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28. Which of the following is a characteristic of RNA viruses?

A) They have a lipid bilayer
B) They replicate in the nucleus
C) They use reverse transcription
D) They are all enveloped

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29. What type of genome does the HIV virus have?

A) Double-stranded DNA
B) Single-stranded RNA
C) Double-stranded RNA
D) Circular DNA

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30. The term “virulence” refers to:

A) The ability of a virus to cause disease
B) The ability of a virus to infect a host
C) The speed of viral replication
D) The resistance of a virus to treatment

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31. The HIV virus enters the host cell by:

A) Phagocytosis
B) Endocytosis
C) Simple diffusion
D) Active transport

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32. Which of the following viral diseases has a vaccine available?

A) HIV
B) Influenza
C) Ebola
D) Hepatitis C

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33. The primary component of the viral envelope is:

A) DNA
B) RNA
C) Lipid
D) Protein

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34. What type of cells are primarily affected by HIV?

A) Neutrophils
B) B cells
C) CD4+ T cells
D) Erythrocytes

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35. Which of the following is an example of a viral family?

A) Bacteria
B) Retroviridae
C) Eukaryota
D) Archaea

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36. The structure that allows a virus to attach to a host cell is known as:

A) Spike protein
B) Capsid
C) Envelope
D) Ribosome

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37. What is the function of reverse transcriptase in HIV?

A) To replicate the viral RNA
B) To convert viral RNA into DNA
C) To synthesize proteins
D) To assemble new virions

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38. Biodiversity loss can result from:

A) Habitat destruction
B) Climate change
C) Pollution
D) All of the above

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39. The primary method of HIV transmission in non-human primates is:

A) Sexual contact
B) Blood exposure
C) Mother-to-child
D) Airborne

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40. What is the role of the immune system in viral infections?

A) It supports viral replication
B) It produces antibodies to fight the virus
C) It provides nutrients to the virus
D) It has no role in viral infections

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41. Which domain of life do viruses belong to?

A) Eukarya
B) Archaea
C) Bacteria
D) None; viruses are not classified in any domain

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42. Which of the following is an example of a zoonotic viral disease?

A) Polio
B) Rabies
C) Smallpox
D) Influenza

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43. The study of the evolutionary relationships among species is known as:

A) Phylogenetics
B) Taxonomy
C) Ecology
D) Biogeography

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44. The term “host range” refers to:

A) The variety of hosts a virus can infect
B) The number of viral strains
C) The number of viral species
D) The geographic distribution of a virus

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45. Which of the following viruses is associated with liver disease?

A) Influenza
B) HIV
C) Hepatitis
D) Measles

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46. The term “antigenic variation” refers to:

A) The change in virus structure that helps it evade the immune system
B) The replication of viral DNA
C) The process of viral entry into host cells
D) The attachment of viruses to host cells

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47. What is the primary method of HIV testing?

A) Urinalysis
B) Skin biopsy
C) Blood test
D) Saliva test

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48. The process by which a virus leaves the host cell after replication is called:

A) Lysis
B) Endocytosis
C) Phagocytosis
D) Fusion

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49. Which of the following statements about viruses is true?

A) They can reproduce on their own
B) They are made up of living cells
C) They can evolve over time
D) They have metabolic processes

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50. The major impact of biodiversity loss includes:

A) Decreased ecosystem stability
B) Increased crop yields
C) Enhanced disease resistance
D) Increased resource availability

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51. The lipid bilayer that surrounds some viruses is called:

A) Cell membrane
B) Envelope
C) Capsid
D) Cytoplasm

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52. The main method by which viruses can enter a host cell is through:

A) Protein synthesis
B) Direct fusion
C) Endocytosis
D) Both B and C

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53. In which stage of HIV infection does the body produce antibodies against the virus?

A) Acute stage
B) Chronic stage
C) Latent stage
D) Symptomatic stage

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54. What type of virus primarily targets the immune system?

A) Oncogenic virus
B) Hepatitis virus
C) Immunodeficiency virus
D) Neurotropic virus

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55. The first successful vaccine against a viral disease was developed for:

A) Polio
B) Measles
C) Smallpox
D) Influenza

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56. Which of the following is NOT a method of viral transmission?

A) Airborne
B) Vector-borne
C) Direct contact
D) Photosynthesis

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57. The process by which a virus incorporates its genetic material into the host’s DNA is called:

A) Replication
B) Transcription
C) Integration
D) Translation

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58. Which of the following is a characteristic of retroviruses?

A) They contain only DNA
B) They use RNA as their genetic material
C) They cannot reverse transcribe
D) They are all enveloped

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59. The primary reason for the emergence of new viral diseases is:

A) Globalization
B) Climate change
C) Genetic mutation
D) All of the above

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60. In the context of biodiversity, what does the term “keystone species” refer to?

A) A species that is the most numerous
B) A species that has a disproportionately large effect on its environment
C) A species that is endangered
D) A species that is invasive

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61. Which of the following is the most effective strategy for managing viral outbreaks?

A) Isolation of infected individuals
B) Vaccination programs
C) Development of antiviral drugs
D) All of the above

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62. The HIV virus primarily targets which type of immune cells?

A) Neutrophils
B) Macrophages
C) CD4+ T cells
D) B cells

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63. Which viral disease is characterized by a high mortality rate and is often transmitted by contact with infected bodily fluids?

A) Influenza
B) Ebola
C) Measles
D) Hepatitis B

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64. The term “biodiversity” refers to:

A) The variety of life forms in a specific area
B) The number of ecosystems in a region
C) The genetic variability within a population
D) All of the above

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65. The first step in viral replication is:

A) Entry into the host cell
B) Assembly of new virions
C) Release from the host cell
D) Integration into the host genome

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66. What is the role of antibodies in the immune response?

A) They provide nutrients to viruses
B) They neutralize or mark pathogens for destruction
C) They help viruses replicate
D) They are produced only in response to bacteria

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67. Which of the following statements about biodiversity is TRUE?

A) Biodiversity is uniform across the globe
B) Biodiversity only refers to the number of species
C) Biodiversity contributes to ecosystem resilience
D) Biodiversity is unrelated to human activity

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68. What is the main reason for the high mutation rate of RNA viruses?

A) They replicate quickly
B) They lack proofreading mechanisms during replication
C) They are exposed to many hosts
D) They are often integrated into the host genome

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69. The “tropism” of a virus refers to:

A) The method of transmission
B) The types of cells or tissues it infects
C) The genetic material it contains
D) The speed of its replication

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70. The most effective way to reduce the risk of HIV transmission is through:

A) Treatment with antibiotics
B) Use of antiviral medications
C) Safe sex practices and condom use
D) Regular blood tests

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71. Which viral disease can lead to liver cancer if left untreated?

A) HIV
B) Hepatitis B
C) Influenza
D) Measles

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72. The classification of HIV is:

A) DNA virus
B) RNA virus
C) Double-stranded virus
D) Bacteriophage

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73. The ability of a virus to mutate and change its surface proteins is a challenge for:

A) Drug development
B) Vaccine efficacy
C) Immune system recognition
D) All of the above

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74. The global effort to conserve biodiversity is known as:

A) Conservation biology
B) Environmentalism
C) Biodiversity management
D) Ecological restoration

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75. What is a common symptom of HIV infection?

A) Fever and fatigue
B) Sore throat and cough
C) Rash and diarrhea
D) All of the above

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76. The term “pathogen” refers to:

A) A virus that can cause disease
B) A harmless microorganism
C) A type of vaccine
D) A method of viral transmission

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77. The ability of an ecosystem to withstand disturbances and recover is referred to as:

A) Resilience
B) Stability
C) Diversity
D) Sustainability

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78. Which of the following diseases can be caused by a virus?

A) Strep throat
B) Chickenpox
C) Tuberculosis
D) Syphilis

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79. The primary host for HIV is:

A) Monkeys
B) Humans
C) Bats
D) Dogs

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80. Which of the following is a method of conserving biodiversity?

A) Habitat preservation
B) Pollution
C) Urbanization
D) Deforestation

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81. Which of the following can serve as a reservoir for viral pathogens?

A) Insects
B) Animals
C) Humans
D) All of the above

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82. Which part of the immune system is primarily responsible for recognizing viruses?

A) B cells
B) T cells
C) Antibodies
D) All of the above

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83. The method by which a virus uses host machinery to replicate is called:

A) Binary fission
B) Viral replication
C) Symbiosis
D) Genetic recombination

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84. Which of the following statements about HIV is TRUE?

A) It can be transmitted through casual contact.
B) It can be cured with antibiotics.
C) It requires a host cell for replication.
D) It is a DNA virus.

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85. The loss of biodiversity can lead to:

A) Ecosystem collapse
B) Increased disease outbreaks
C) Loss of ecosystem services
D) All of the above

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86. The primary role of the immune response in viral infections is to:

A) Allow for viral replication
B) Protect the host from the virus
C) Produce more viruses
D) None of the above

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87. The basic unit of classification in biology is the:

A) Family
B) Genus
C) Species
D) Order

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88. The mechanism by which viruses acquire an envelope is through:

A) Protein synthesis
B) Budding from the host cell
C) Binary fission
D) Phagocytosis

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89. Which of the following factors does NOT threaten biodiversity?

A) Climate change
B) Pollution
C) Sustainable farming
D) Habitat loss

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90. Which of the following is a common treatment for HIV?

A) Antiretroviral therapy (ART)
B) Antibiotics
C) Antifungal medications
D) Vaccines

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91. What is the main function of the viral envelope?

A) To protect the genetic material
B) To facilitate attachment to host cells
C) To assist in replication
D) To store viral proteins

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92. The primary focus of conservation efforts is to:

A) Increase agricultural yields
B) Maintain biodiversity
C) Promote urban development
D) Enhance economic growth

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93. The first viral disease for which a vaccine was developed is:

A) Polio
B) Smallpox
C) Measles
D) Hepatitis

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94. Which of the following methods is used to diagnose viral infections?

A) X-rays
B) Blood tests
C) Urinalysis
D) Physical examination

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95. The term “biodiversity conservation” refers to:

A) The protection of ecosystems and species
B) The study of viral genetics
C) The treatment of viral diseases
D) The classification of microorganisms

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96. Which of the following is NOT a function of the capsid?

A) Protects viral genetic material
B) Assists in viral entry into host cells
C) Provides energy for viral replication
D) Facilitates the attachment to host cells

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97. Which virus is known for its ability to cause chronic infections?

A) Influenza
B) Hepatitis C
C) Measles
D) Norovirus

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98. The primary mode of action of antiviral drugs is to:

A) Destroy host cells
B) Inhibit viral replication
C) Enhance the immune response
D) Promote viral entry into cells

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99. The loss of genetic diversity within a species can lead to:

A) Increased adaptability
B) Higher extinction rates
C) Improved survival
D) None of the above

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100. The concept of “One Health” refers to:

A) The interconnection between human, animal, and environmental health
B) The health of a single species
C) The treatment of individual diseases
D) The classification of organisms

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