Free Introduction to Biology MCQs with Answers

81. Which one of the following is a correct sequence in biological methods?

• A. Observations - Hypothesis - Law - Theory
• B. Observations - Hypothesis - Deduction - Experimentation
• C. Hypothesis - Observations - Deduction - Experimentation
• D. Law - Theory - Deduction - Observations

Explanation: The correct sequence in the scientific method is observation, hypothesis, deduction, and experimentation. You start by observing phenomena, then propose a hypothesis to explain them. Next, you deduce predictions that can be tested, and finally, you perform experiments to see if the predictions hold true. Other options are incorrect because they either place steps out of order or include terms like 'law' and 'theory,' which are not steps in the scientific method but rather results that can emerge from it.

82. The science of biology has been helping mankind in which of the following ways?

• A. Increasing food production
• B. Combating disease
• C. Conservation of the environment
• D. All of these

Explanation: The correct answer is all of these. Biology significantly contributes to various fields that benefit humanity. Through genetic modification and agricultural biology, it helps increase food production. Medical biology and biotechnology have been pivotal in combating diseases by developing treatments and preventive measures. Additionally, environmental biology promotes the conservation of ecosystems and biodiversity. Each option represents a distinct way biology aids mankind, and collectively, they underscore the breadth of biology's impact. Therefore, selecting 'All these' encapsulates the comprehensive influence of biology.

83. Plant and animal breeders have developed new methods by which of the following?

• A. Selective breeding
• B. Using principles of genetics
• C. Biological control
• D. Both a and b

Explanation: The correct answer is 'Both a and b.'. Plant and animal breeders utilize both selective breeding and principles of genetics to develop new, improved breeds. Selective breeding involves choosing specific parents to enhance certain traits, while genetics helps understand and apply heredity laws to achieve desired outcomes. Biological control is unrelated to breeding, as it focuses on pest management.

84. One of the most common sources of getting quick and cheap white meat is?

• A. Chicken
• B. Broiler
• C. Cow
• D. Sheep

Explanation: The correct answer is broiler. Broilers are chickens that are specifically bred for meat production and are known for their fast growth and cost-effectiveness, making them a popular choice for quick and inexpensive white meat. The other options are incorrect: ' 'Chicken' is broad, as it includes both meat and egg-laying varieties, whereas the term 'broiler' specifically refers to meat production. Cows and sheep are sources of red meat and are not typically associated with the terms 'quick' and 'cheap' in the context of meat production.

85. Genes of disease resistance and other desirable characters are introduced into plants by using:

• A. Genetic engineering
• B. Cloning
• C. Gene therapy
• D. Biological

Explanation: The correct answer is genetic engineering. This process involves the manipulation of an organism's genome using biotechnology to introduce desirable traits, such as disease resistance, into plants. This method is widely used in agricultural biotechnology to enhance plant characteristics.Cloning simply creates identical copies of an organism and does not introduce new genetic traits. Gene therapy is a technique used for correcting defective genes responsible for disease development, primarily in humans and animals, not plants. The option biological is too broad and does not specify any method related to gene introduction.

86. Plants having foreign DNA incorporated into their cells are known as what?

• A. Clones
• B. Transgenic plants
• C. Eugenic plants
• D. Mutants

Explanation: The correct answer is transgenic plants. These are plants that have been genetically modified to include DNA from another species, providing them with new traits. This is different from clones, which are simply identical copies of the parent organism without new DNA. Eugenic plants is not a recognized term in biology related to genetic modification. Mutants are organisms with mutations, which are changes in their own DNA, not necessarily involving foreign DNA.

87. All of the following do not produce a transgenic organism except?

• A. Introduction of the desired gene into the organism
• B. Replacement of the nucleus of an unfertilized egg with a diploid nucleus of a somatic cell
• C. Produced from a zygote
• D. Asexual reproduction

Explanation: The correct answer is the introduction of a desired gene into the organism. This method creates transgenic organisms by inserting new genetic material into their DNA to express desired traits. In contrast, the replacement of a nucleus with a somatic cell nucleus, a process used in cloning, does not involve genetic modification to introduce new traits. Similarly, organisms produced from a zygote or through asexual reproduction do not automatically entail the genetic modifications necessary to form transgenic organisms.

88. Astronauts may use it for growing vegetables?

• A. Tissue culture technique
• B. Hydroponic culture technique
• C. Biological control
• D. All of these

Explanation: Astronauts may use hydroponics for growing vegetables in space. Hydroponics is a method of cultivating plants without soil, using nutrient-rich water solutions instead. This technique is ideal for space missions because it saves space, reduces the need for soil transport, and allows precise control over nutrients and water. In the controlled environment of a spacecraft or space station, hydroponic systems provide the necessary conditions for plants to grow, such as proper light, humidity, and temperature. Growing vegetables through hydroponics not only helps supply fresh food for astronauts but also contributes to recycling carbon dioxide and producing oxygen, making it an important part of long-duration space exploration.

89. He first developed the technique of vaccination.

• A. Louis Pasteur
• B. Edward Jenner
• C. Gregor Mendel
• D. Beadle and Tatum

Explanation: Edward Jenner is considered the pioneer of the vaccination technique. In 1796, he demonstrated that exposure to cowpox could provide immunity to smallpox, laying the foundation for modern immunology. The other options, while significant figures in biology, are not linked to the original development of vaccination. Louis Pasteur later expanded upon Jenner's work, Gregor Mendel is known for genetics, and Beadle & Tatum are known for their genetic research.

90. The technique used to replace a defective gene with a normal gene is known as?

• A. Cloning
• B. Gene therapy
• C. Genetic engineering
• D. Chemotherapy

Explanation: This question tests knowledge of genetic medicine, essential for medical students in biochemistry and molecular biology. Gene therapy is completely correct, as it specifically involves replacing defective genes with normal ones to treat genetic disorders. Other options refer to unrelated or broader processes, risking misunderstanding of targeted genetic interventions.