All Free Biology MCQs with Answers

• A. Mitochondria
• B. Lysosome
• C. Plastids
• D. Ribosome

Explanation: Mitochondria are powerhouses of a cell. Aerobic cellular respiration takes place in mitochondria.

• A. Cisternae
• B. Cristae
• C. Lemma
• D. Tonoplast

Explanation: Cristae are folds in the inner mitochondrial membrane.

• A. Active transport
• B. Passive transport
• C. Osmosis
• D. Diffusion

Explanation: Active transport is a type of transmembrane transport that moves molecules across a cell membrane against their concentration gradient. This requires energy, which is usually provided in the form of ATP.

• A. Cell wall
• B. Golgi
• C. Mitochondria
• D. Nucleoid

Explanation: The cell walls of prokaryotes have a unique macromolecule called peptidoglycan. Its amount varies in different types of bacteria. It is composed of a framework of long glycan chains cross-linked with peptide fragments. The intact cell wall also contains chemical constituents such as sugar molecules, teichoic acid, lipoproteins, and lipopolysaccharides, which are linked to peptidoglycan. The most distinctive feature of the prokaryotic cell is its cell wall, composed of polysaccharide chains bound covalently to shorter chains of amino acids forming peptidoglycan or murein. The entire cell wall is often regarded as a single huge molecule or molecular complex called a sacculus The cell wall of plants is generally made up of cellulose and is differently structured than that of a bacterium.

• A. Smooth endoplasmic reticulum
• B. None of these
• C. Both of these
• D. Rough endoplasmic reticulum

Explanation: Outer nuclear membrane is continuous with rough endoplasmic reticulum.

• A. Magnification
• B. Contrast
• C. Resolving power
• D. Scanning power

Explanation: Resolving power or resolution is the ability to distinguish objects that are close together. The better the resolving power of the microscope, the closer together two objects can be and still be seen as separate.

• A. Cytoplasm
• B. Nucleoplasm
• C. Protoplasm
• D. Protoplast

Explanation: The nucleoplasm is a type of protoplasm that makes up the cell nucleus, the most prominent organelle of the eukaryotic cell. Nucleoplasm is also known as karyoplasm, karyolymph, or nucleus sap.

• A. Rough endoplasmic reticulum
• B. Golgi complex
• C. Ribosomes
• D. All of the above options are correct

Explanation: This statement is true. All the options listed (rough endoplasmic reticulum, golgi complex, and ribosomes) are involved in protein synthesis in their respective ways. The rough endoplasmic reticulum provides the site for initial protein synthesis, the golgi complex processes and modifies the proteins, and ribosomes are the essential machinery where the actual synthesis of proteins occurs.

• A. 1 mm
• B. 2 dm
• C. 0.1 mm
• D. 1 dm

Explanation: Human eye can differentiate between two points that are 1 mm away. When distance is less than 1 mm, naked human eye cannot differentiate it and microscope is needed for that.

• A. Synthesis of intracellular proteins
• B. Synthesis of extracellular proteins
• C. Synthesis of extracellular enzymes
• D. Synthesis of lipids

Explanation: Option D is correct . SER is responsible for lipid metabolism.