All Free Biology MCQs with Answers

• A. 3-phosphoglycerate
• B. 1,3- biphosphogylcerate
• C. Glyceraldehyde -3-phosphate
• D. Glucose

Explanation: In the second stage, ATP and NADPH are used to convert the 3-PGA molecules into molecules of a three-carbon sugar…

• A. Proteins
• B. Lipids
• C. Chlorophylls
• D. Enzymes

Explanation: Magnesium is a key component of chlorophyll, the green colouring material of plants, and is vital for photosynthesis.

• A. Stroma
• B. Thylakoid
• C. Matrix
• D. Cisternae

Explanation: This is where the components of the electron transport chain are located.

• A. ATP and NADP+
• B. ADP and NADP+
• C. ADP and NADPM
• D. ATP and NADPH

Explanation: After the completion of light reactions in photosynthesis, the molecules released and utilized in the dark reactions are ATP and NADPH…

• A. It induces photolysis
• B. Gains Hydrogen
• C. Accept elecrons
• D. It is oxidised

Explanation: When light falls on P-700, it is oxidised. The electrons are removed.

• A. ATP and NADPH
• B. ATP and glucose
• C. Glucose and NADP
• D. ATP and water

Explanation: These molecules are generated during the light reactions and are used in the subsequent dark reactions to convert carbon dioxide into…

• A. Plastoquinone
• B. Cytochrome - C
• C. Plastocyanin
• D. Ferredoxin

Explanation: It serves as an electron transfer agent between the cytochrome complex which follows Photosystem II and the entry point to Photosystem I…

• A. Magnesium
• B. Iron
• C. Chlorine
• D. Oxygen

Explanation: "The explanation for this question will be added soon!".

• A. 0.2
• B. 0.15
• C. 0.05
• D. 0.01

Explanation: Only 1% of light is absorbed by the leaf.

• A. Water potential
• B. Cohesion tension
• C. Root pressure
• D. Imbibition

Explanation: "The explanation for this question will be added soon!".

• A. Cohesion
• B. Tension
• C. Adhesion
• D. Imbibition

Explanation: Option A: Cohesion refers to the attraction between water molecules themselves, which allows them to stick together and form a continuous…

• A. Chlorophyll a
• B. Chlorophyll b
• C. Chlorophyll c
• D. None of these

Explanation: Chlorophyll a is the most abundant pigment in plants and algae. It is a blue-green pigment that absorbs blue and red light during…

• A. Oxygen
• B. Carbon dioxide
• C. Water
• D. Light

Explanation: Correct option is B. During photosynthesis, plants take in carbon dioxide (CO2) and water (H2O) from the air and soil.

• A. Stroma
• B. Grana
• C. Thylakoid
• D. Intergrana

Explanation: The correct answer for this is "Thylakoid". Since chlorophyll is a pigment present in the chloroplast, It is present and embedded in the…

• A. Plasmid
• B. Genes
• C. Chromosomes
• D. Histone

Explanation: The cellular DNA of a bacterium is plasmid- extranuclear small double-stranded DNA molecules.

• A. Chromosomes
• B. Nucleus
• C. Centrosome
• D. Mesosomes

Explanation: Mitosis cannot take place in bacteria because they lack nucleus. Nucleus consists of multiple chromosomes that replicate and result in…

• A. Polysome
• B. Endosome
• C. Mesosome
• D. Centrosome

Explanation: Mesosome is a convoluted membranous structure formed in a prokaryotic cell by the invagination of the plasma membrane.

• A. Flagella
• B. Capsule
• C. Pilli
• D. Mesosomes
• E. Nucleoid

Explanation: Explanation for this question will be added soon.

• A. Absence of membrane bound organelles
• B. Absence of nucleus
• C. Presence of 70S ribosomes
• D. All of these

Explanation: Option D is correct since a prokaryotic cell does not have membrane-bound cellular organelles and a nucleus. It contains 70S ribosomes.

• A. 80s ribosomes
• B. Cell wall
• C. Cell membrane
• D. Golgi apparatus

Explanation: Ribosomes are used by the cells for the translation of mRNA to produce proteins.