All Free Biology MCQs with Answers

• A. Ribosome
• B. Mitochondria
• C. Nucleus
• D. Centriole

Explanation: Therefore, the correct answer is B) Mitochondria, as they are the organelles primarily involved in ATP synthesis within the cell.

• A. Galactose
• B. Glucose
• C. Phospholipid
• D. Carbohydrate

Explanation: The plasma membrane comprises phospholipid molecules, referred to as fluid in the fluid mosaic model.

• A. Cell wall
• B. Nucleus
• C. Cytoplasm
• D. Mitochondria

Explanation: In a plant cell, the cell wall is the only part that is non-living because it is an extracellular product and exists outside the living boundary of the cell i.e. the plasma membrane, and protects the cell besides providing it a definite shape.

• A. Passive Diffusion
• B. Active Transport
• C. Endocytosis
• D. Facilitated Diffusion

Explanation: Facilitated diffusion also known as facilitated transport or passive-mediated transport, is the process of spontaneous passive transport of molecules or ions across a biological membrane via specific trans-membrane integral proteins.

• A. Prokaryotes
• B. Protists
• C. Animal
• D. Plants

Explanation: Plant cells unlike any other possess a large central vacuole. The central vacuole stores water and maintains turgor pressure in a plant cell. It also pushes the contents of the cell toward the cell membrane, which allows the plant cells to take in more light energy for making food through photosynthesis

• A. Smooth Endoplasmic Reticulum
• B. Rough Endoplasmic Reticulum
• C. Golgi apparatus
• D. Lysosomes

Explanation: The detoxification of drugs is the function of SER while protein synthesis is the function of RER. Mechanical support, however, is the function of both RER AND SER.

• A. Centriole
• B. Endoplasmic Reticulum
• C. Nucleus
• D. Ribosome

Explanation: The ribosome is present in both prokaryotes and eukaryotes, eukaryotes have 80s while prokaryotes have 70s ribosomes.

• A. Single, circular, double stranded molecule not bound by membrane
• B. Double, circular molecule
• C. Linear, double stranded molecule
• D. Single, circular, double stranded and membrane bound

Explanation: Prokaryotes lack membrane-bound organelles so, DNA is not bound by a membrane, and DNA in prokaryotes is a single, circular double strand.

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

Explanation: Cristae are the folds of the inner membrane of mitochondria.The inner membrane of mitochondria is where most of the cellular respiration takes place. The cristae increase the surface area of the inner membrane, which allows for more efficient cellular respiration. This is because the cristae provide more space for the proteins and enzymes that are involved in cellular respiration.In addition to increasing the surface area of the inner membrane, the cristae also help to anchor the proteins and enzymes that are involved in cellular respiration. This helps to keep the proteins and enzymes in the correct position so that they can function properly.

• A. Fungi
• B. Algae
• C. Virus
• D. Microbes

Explanation: Here are some of the reasons why the cell theory is not applicable to viruses:Viruses do not have a cell membrane. A cell membrane is a structure that surrounds all cells and provides protection and support. Viruses do not have a cell membrane, and they are instead surrounded by a protein coat.Viruses do not have their own metabolism. Metabolism is the process by which cells convert energy and nutrients into molecules that the cell can use. Viruses do not have their own metabolism, and they rely on the host cell to provide them with the energy and nutrients they need to survive.Viruses do not reproduce on their own. Cells can reproduce by dividing in half. Viruses cannot reproduce on their own, and they need to infect a host cell in order to reproduce.