Free Introduction to Biology MCQs with Answers

• A. Inductive reasoning
• B. Deductive reasoning
• C. Hypothesis
• D. Science

Explanation: Deductive reasoning starts from general statements (all birds have wings) and applies them to specific cases (sparrows) to reach a logical…

• A. 10%
• B. 90%
• C. 99%
• D. 9%

Explanation: The six commonest bioelements (oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus) account for about 99% of the human body's…

• A. 92
• B. 16
• C. 4
• D. 104

Explanation: Bioelements are the chemical elements that are essential for the structure and function of living organisms.

• A. Study of animals
• B. Study of plants
• C. Study of atoms and molecules
• D. Study of bacteria and virus

Explanation: The study of atoms and molecules primarily falls under the field of chemistry, not biology.

• A. Ethologist
• B. Embryologist
• C. Biologist
• D. Biotechnologist

Explanation: Biologists study living organisms and their interactions with the environment, including non-living elements that affect them.

• A. Hydrogen
• B. Carbon
• C. Magnesium
• D. Oxygen

Explanation: Carbon is the second most abundant bioelement in living organisms, forming the backbone of organic compounds.

• A. Zinc
• B. Copper
• C. Calcium
• D. Manganese

Explanation: Calcium is not just found in trace amounts; it is present in larger quantities as it is crucial for bone and teeth formation, muscle…

• A. Hydrogen
• B. Carbon
• C. Nitrogen
• D. Oxygen

Explanation: Oxygen is the most abundant element in the human body by mass, primarily because it is a major component of water, which makes up a…

• A. Root
• B. Leaf
• C. Stem
• D. Flower

Explanation: Flowers are the reproductive organs of plant where sexual reproduction occurs, leading to the formation of seeds.

• A. Species
• B. Individuals
• C. Biosphere
• D. Population

Explanation: A species is a group of organisms that can potentially interbreed and produce fertile offspring.

• A. Species
• B. Population
• C. Community
• D. Biosphere

Explanation: A community is a dynamic collection of different species living together and interacting in a particular area.

• A. Ecosystems
• B. Biosphere
• C. Biomes
• D. All these

Explanation: Biomes are large geographical biotic units, a major community of plants and animals with similar life forms and environmental conditions.

• A. 3000 Million
• B. 2000 Million
• C. 600 Million
• D. 225 Million

Explanation: Scientific evidence suggests that the earliest life forms appeared around 3 billion years ago.

• A. Zero
• B. Equal to the younger sediment layer
• C. Less than the younger sediment layer
• D. Greater than the younger sediment layer

Explanation: Radioactive decay decreases the number of isotopes in older layers compared to younger ones.

• A. Millions
• B. 30 million
• C. 2.5 million
• D. 3 million

Explanation: So far, scientists have identified and named about 2 to 2.5 million species of plants, animals, fungi, protists, and microorganisms.

• A. 25%
• B. 53.1%
• C. 19.9%
• D. 17.6%

Explanation: There are nearly 2.5 million species of organisms currently known to science.

• A. Sheep
• B. Mice
• C. Cows
• D. All these

Explanation: All these species: sheep, mice, and cows have been successfully cloned, showcasing diverse applications in research and agriculture.

• A. Has helped mankind to raise the standard of living
• B. Has destroyed our environment
• C. Both A and B
• D. None of these

Explanation: Industrialization has helped mankind to raise the standard of living by providing more goods, services, jobs, and technologies.

• A. Bioabsorption
• B. Bioremediation
• C. Cloning
• D. Chemotherapy

Explanation: Bioremediation is the process by which living organisms, such as plants or microbes, break down hazardous substances into less toxic or…

• A. Environmental biology
• B. Microbiology
• C. Ecology
• D. Freshwater biology

Explanation: Freshwater biology is the branch of biology that deals with the study of organisms living in freshwater bodies such as rivers, lakes, and…