All Free Biology MCQs with Answers

• A. Group of cells
• B. Group of organs
• C. Group of tissues
• D. Group of organisms

Explanation: Tissue is a group of cells that have similar structure and that function together as a unit.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Option D is the only option that makes sense. Suicide sacs are lysosomal enzymes that are membrane bound. Mitochondria and golgi apparatus are also membrane bounded organelles.

• A. These are small structures which work like oars
• B. It is covered with plasma membrane
• C. It's core is called axoneme
• D. All of the above

Explanation: Cilia and flagella are hair-like outgrowths of the cell membrane. Cilia are small structures working like oars, causing the movement of either the cell or the surrounding fluid. Flagella, in comparison, is longer and is responsible for cell movement. Both cilium and flagellum are covered with plasma membrane. Their core, called axoneme, possesses a number of microtubules running parallel to the long axis.So, the correct answer is 'All of the above'.

• A. I only
• B. I&II
• C. II & III
• D. II & IV
• E. III & IV

Explanation: Nucleus is the control centre of the cell and stores the genetic material of the cell,so we say that statements II and IV are correct, making option D correct. Nucleus does not store wastes and other substances plus it also does not help in cellular transport system, that eliminate option A,B,C and E.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Mitochondria, cytoplasm and nucleus are found in both plant and animal cells. However, chloroplast is the organelle found in plant cells but lacking in animal cells.

• A. Schleiden & Schwann
• B. Galileo
• C. Robert Hooke
• D. Robert Brown

Explanation: This is purely factual recall. The cell was first discovered and named by Robert Hooke in 1665.

• A. Phospholipids
• B. Glycolipids
• C. Proteins
• D. Carbohydrates

Explanation: The correct answer is Proteins. The fibers of the extracellular matrix attach to proteins known as integrins within the plasma membrane. Integrins span the membrane and connect to both extracellular matrix proteins and intracellular cytoskeletal proteins, enabling the cell to transmit signals and maintain its structure. Phospholipids form the bilayer of the membrane but are not directly involved in binding the matrix fibers. Glycolipids, with their role in cell recognition, and Carbohydrates, involved in signaling, do not serve as attachment points for the extracellular matrix.

• A. Phospholipids
• B. Glycoproteins
• C. Lipoproteins
• D. Nucleoproteins

Explanation: Lipoproteins formed by the combination of lipids and proteins serve as the basic structural framework of all types of membranes in the cells.

• A. 100 x
• B. 300 x
• C. 400 x
• D. 500 x

Explanation: Resolution is the measurement of the number of pixelsNaked eye resolution is 576 Megapixels which is 500 times the resolution of compound microscopeThe resolution of the naked eye refers to its ability to distinguish and perceive fine details or distinguish between two closely spaced objects. The resolution of the human eye is limited by several factors, including the number of photoreceptor cells in the retina and the optics of the eye.On average, the human eye can resolve objects that are approximately 1 arcminute apart. This means that if two objects are separated by an angle of 1 arcminute (which is 1/60th of a degree), a person with normal vision would be able to perceive them as separate entities rather than a single object.

• A. Central Vacuole, Cell Membrane, Ribosomes
• B. Chloroplast, Ribosome , Mitochondria
• C. Cell wall, Chloroplast, Central vacuole
• D. Ribosome, Mitochondria, Cell wall

Explanation: Animal cells do not have a Cell wall and Chloroplasts. They have temporary small vacuoles; unlike plant cells which have large, permanent, central vacuoles.In the other options, at least one feature is present in the animal cells instead of all the three features pertaining to animal cells. The idea is to choose the better answer.The diagram presented below shows the major organelles in an animal cell; Flexibility and Mobility: Animal cells are often required to move and change shape, which is facilitated by their flexible cell membrane. The absence of a rigid cell wall allows animal cells to have more flexibility and mobility compared to cells with a cell wall. This flexibility is essential for various cellular processes, including cell migration, muscle contraction, and the ability to form complex tissues and organs.Intercellular Communication: Animal cells rely on direct cell-to-cell communication through specialized structures like gap junctions and tight junctions. These junctions facilitate the exchange of signals, ions, and molecules between neighboring cells, allowing for coordinated responses and tissue organization. A cell wall would hinder the direct interaction between animal cells and impede the efficient communication required for their complex physiological processes.Structural Support: In the absence of a cell wall, animal cells utilize the cytoskeleton, a network of protein filaments, to maintain their structural integrity and provide support. The cytoskeleton allows animal cells to maintain their shape, organize their internal components, and carry out cellular functions. This dynamic framework provides mechanical strength while allowing flexibility and shape changes.Adaptation to Environment: Animals have evolved to inhabit diverse environments and face varying physical conditions. The absence of a rigid cell wall enables animal cells to adapt to different osmotic pressures, temperature changes, and other environmental factors. Animal cells can regulate their volume and shape in response to external stimuli, allowing them to survive and function effectively in their respective environments.It's important to note that while animal cells lack a cell wall, they still possess a cell membrane (plasma membrane) that separates the cell's internal environment from the external environment. The cell membrane is a selectively permeable barrier that controls the passage of substances in and out of the cell.