All Free Biology MCQs with Answers

• A. Iron
• B. Chlorine
• C. Copper
• D. Potassium

Explanation: The correct answer is potassium. Potassium is classified as a macromineral, not a micronutrient.

• A. Xylem
• B. Phloem
• C. Cortex
• D. Epidermis

Explanation: The cambium is a layer of actively dividing cells in plants that contributes to secondary growth by producing new cells.

• A. 500 mg
• B. 400 mg
• C. 800 mg
• D. 1800 mg

Explanation: Phosphorus is crucial for numerous bodily functions, including the formation of bones and teeth, and it plays a role in how the body uses…

• A. K-Mg-N-P
• B. Cu-Mg-Mn-S
• C. Mn-S-P-Cu
• D. Mg-Mn-Ca-P

Explanation: The macronutrients are K-Mg-N-P (Students should learn this as it is a fact)

• A. Cu ions
• B. Ca ions
• C. Mg ions
• D. K ions

Explanation: The correct answer is Cu ions. Macronutrients are elements required in large quantities for plant growth.

• A. Plastocyonin
• B. Cytochromes
• C. Plastoquinones
• D. All of the above

Explanation: Plastoquinones are molecules that serve as electron carriers in the process of photosynthesis.

• A. Chlorophyll a
• B. Chlorophyll r
• C. Chlorophyll b
• D. Chlorophyll d

Explanation: Chlorophyll a is a pigment found in the chloroplasts of plant cells. It absorbs light energy from the sun, particularly in the blue and…

• A. Industrial fixation
• B. Biological fixation
• C. Atmospheric fixation
• D. All of the above

Explanation: In industrial fixation, nitrogen gas (N2) is converted into a usable form, such as ammonia (NH3), through a process called the Haber-Bosch…

• A. Buds
• B. Seeds
• C. Root and underground stem
• D. All of the above

Explanation: The term "Sink of assimilate" is used to describe various plant parts like seeds, buds, and underground stems.

• A. Chlorophyll A
• B. Chlorophyll B
• C. Chlorophyll C
• D. Chlorophyll D

Explanation: The above formula represents the structure of chlorophyll b. Chlorophyll b is a pigment found in plants and algae that plays a key role in…

• A. Hydroelectric power
• B. Nuclear power
• C. Solar energy
• D. Fossil fuels

Explanation: Fuels that are generated very deep under the earth from the debris of plants and animals, which existed millions of years ago, are called…

• A. Mechanical forming
• B. Improved crop varieties
• C. Continuous photosynthesis
• D. Pest control

Explanation: Food is considered a renewable resource primarily because of continuous photosynthesis, which allows plants to convert sunlight into…

• A. Carolers forming
• B. Extensive ploughing
• C. Moderate grazing
• D. Heavy grazing

Explanation: Moderate grazing refers to controlled or balanced grazing practices where the number of livestock and their grazing duration are managed…

• A. Methane
• B. Sulpher dioxide
• C. Nitrogen dioxide
• D. Ethane

Explanation: Solid wastes are biologically converted into value added products by physiological action of microorganisms.

• A. Forests
• B. Iron
• C. Petroleum
• D. Natural gas

Explanation: Forests are not considered non-renewable resources of energy. Forests have various uses and can provide energy through biomass, they are…

• A. troposphere
• B. stratosphere
• C. mesosphere
• D. atmosphere

Explanation: Ozone Layer: It is a thin part of Earth's atmosphere that absorbs almost all of the sun's harmful ultraviolet light.

• A. Alphine forests
• B. Boreal forests
• C. Arctic tundra
• D. Alpine tundra

Explanation: Among all the options, alpine tundra is at the highest elevation (about 12000 ft and above), and it has the most sunlight hours.

• A. Forest
• B. Nuclear power
• C. Oil
• D. Coal

Explanation: Non-renewable resources are natural resources that cannot be easily replenished or regenerated within a short period of time.

• A. 40S
• B. 60S
• C. 70S
• D. 80S

Explanation: 70S: This option is correct because prokaryotic cells have ribosomes made up of a small 30S subunit and a large 50S subunit, totaling 70S.

• A. 1%
• B. 2%
• C. 3%
• D. 4%

Explanation: Bacterial cells are prokaryotic and lack the complex structures found in eukaryotic cells.