MCQs on Cell Organelles: Solution & Explanation

Ans. (a) Golgi Apparatus

Explanation: The Golgi apparatus, also known as the Golgi Body or Golgi complex, is a type of organelle that functions as a major packing location for chemicals that will be dispersed throughout the cell. It's found in the cytoplasm, which is close to the nucleus and next to the endoplasmic reticulum.

Other options:

• b) Mitochondria are responsible for producing energy in the form of ATP. 
• c) Vacuoles are storage sacs that can hold water, nutrients, waste products, and other substances.
• d) Plastids are responsible for photosynthesis, food storage, and other plant functions.

Ans. (c) Cytoplasm

Explanation: The cytoplasm is a jelly-like substance inside the cell that contains other organelles. A viscous liquid that fills each cell and surrounds it with the cell membrane, the cytoplasm is in charge of retaining cellular components together and protecting them from damage. The cytoplasm has a pH of 7.4.

Other options:

• a) Ectoplasm is a term that is sometimes used to refer to the outer layer of the cytoplasm, but it is not a precise scientific term.
• b) Nucleoplasm specifically refers to the substance within the nucleus, not the entire cell.
• d) The correct term for the substance inside the cell is cytoplasm.

Ans. (d) Prokaryotes

Explanation: Prokaryotes have a single chromosome and divide their cells by fission or budding. Binary fission, or in short budding is the most common method of prokaryote cell division. Prokaryotes have a single chromosome, which replicates before attaching each copy to a different part of the cell membrane.

Other options:

• a) Bacteria is a type of prokaryote. Whereas, the question asks for a specific organism, and bacteria is a broad category.
• b) Eukaryotes have multiple chromosomes, so they don't fit the description.
• c) The term "primitive organism" is a vague term and is not a scientific classification.

Ans. (a) Cytoskeleton

Explanation: The cytoskeleton is a network of protein fibres that provides structural support and maintains the cell's shape. It is also involved in cell movement and intracellular transport.

Other options:

• b) Endoplasmic reticulum is a network of membranes involved in protein synthesis and lipid metabolism.
• c) Lysosomes are organelles that contain enzymes that break down macromolecules. 
• d) Peroxisome are organelles that contain enzymes that break down hydrogen peroxide, a toxic molecule.

Ans. (c) Plasma Membrane

Explanation: The plasma membrane serves as the cell's outermost barrier. It's also referred to as the cell membrane. The membrane that separates the interior of the cell from the outer environment is found in all cells. In bacterial and plant cells, the cell wall is linked to the plasma membrane on its exterior surface.

Other options:

• a) Cytoplasm is the gel-like substance inside the cell, not the outer boundary.
• b) The nuclear membrane surrounds the nucleus, not the entire cell.
• d) The correct answer is the plasma membrane.

Ans. (a) Osmosis

Explanation: Osmosis is a passive process that occurs without the need for any energy. It requires moving molecules from a higher concentration zone to a lower concentration zone until both sides of the membrane have equal concentrations. Any solvent, including gases and supercritical liquids, can go through the osmosis process.

Other options:

• b) Diffusion refers to the movement of solutes, not specifically water.
• c) Osmosis is a type of diffusion, making option (c) incorrect.
• d) While both osmosis and diffusion occur, they are distinct processes.

Ans. (b) Endocytosis

Explanation: The process in which the chemicals are being internalised into a cell is known as endocytosis. The material is encircled by the cell membrane before forming a vesicle inside the cell. Endocytosis includes pinocytosis and phagocytosis. With the help of pseudopodia, the amoeba consumes its food through the process of endocytosis.

Other options:

• a) Diffusion is the passive movement of substances from high to low concentration.
• c) Egestion is the process of expelling indigestible material, not consuming.
• d) Osmosis specifically involves the movement of water, not material consumption.

Ans. (b) Prokaryotic

Explanation: Cyanobacteria, often known as blue-green algae, are microscopic organisms that can be found in all types of water naturally. Fresh, brackish, and marine water are all home to these eukaryotic single-celled creatures. These organisms create their own nourishment by absorbing sunlight. Cyanobacteria may multiply swiftly in warm, nutrient-rich (heavy in phosphorus and nitrogen) settings, forming blooms that spread across the water's surface.

Other options:

• a) Eukaryotic cells have a nucleus, which blue-green algae lack.
• c) Blue-green algae are prokaryotic, not eukaryotic.
• d) The correct answer is prokaryotic.

Ans. (d) Exocytosis

Explanation: Exocytosis is the process of vesicles fusing with the plasma membrane and releasing their contents into the cell's external environment. Exocytosis is the process by which cells direct the contents of secretory vesicles out through the cell membrane. These vesicles include soluble proteins that are discharged into the extracellular environment, as well as lipids and membrane proteins that are transmitted to turn cell membrane components.

Other options:

• a) Osmosis is the movement of water across a membrane.
• b) Endocytosis involves bringing substances into the cell, not releasing them.
• c) Diffusion is the movement of substances from high to low concentration.

Ans. (c) Chloroplast and Mitochondria 

Explanation: Mitochondria and Chloroplast are both prokaryotic cell-like structures. Prokaryotic cells are single-celled microorganisms that are thought to be among the oldest on the planet. Bacteria and Archaea are examples of prokaryotes. All processes happen within the cytoplasm of a prokaryotic cell because it only has one membrane. They might be parasitic or free-living.

Other options:

• a) Chloroplast alone is correct, but mitochondria should also be considered.
• b) None of these is incorrect; mitochondria and chloroplasts resemble prokaryotic cells.
• d) Mitochondria alone is correct, but chloroplasts should also be considered.

Ans. (a) Cell Biology

Explanation: Cell biology is a discipline of biology concerned with the structure and function of cells, as well as how they develop, divide, differentiate, and specialise. Cell biology defines both the general traits that most cell types share and the distinctive features that allow specialised cells to execute specific functions.

Other options:

• b) Microbiology deals with microorganisms, not specifically cells.
• c) Biotechnology involves the use of living organisms for practical applications.
• d) Biology includes the study of living organisms, however, it's too broad to specifically address cells.

Ans. (c) Vacuoles

Explanation: Vacuoles are used to store and dispose of a variety of chemicals. These organelles have the ability to store food and other nutrients that a cell needs to thrive. They also function as trash storage and contamination protection for the entire cell. Plant cells have larger vacuoles than animal cells, with vacuoles taking up more than 80% of the cell's volume.

Other options:

• a) Lysosomes are responsible for digestion and waste removal, not food storage.
• b) Mitochondria are involved in energy production, not food storage.
• d) The cell membrane is a boundary structure; it does not store nutrients.

Ans. (b) Centrosome

Explanation: The centrosome is a microtubule-organising organelle found in animal cells. It also has an effect on the cell cycle. Two microtubule rings called centrioles make up a centrosome. Its principal job is to keep the microtubules organised and help to give the cell structure. During cell division, it also separates the chromatids.

Other options:

• a) The Golgi body is present in both animal and plant cells.
• c) The nucleus is a fundamental organelle found in both types of cells.
• d) All of the above is incorrect as the centrosome is specific to animal cells.

Ans. (d) Lysosomes

Explanation: Lysosomes serve as the cell's waste disposal structures, digesting and degrading unwanted items from the outside as well as waste elements within the cell. However, the digesting enzymes can sometimes damage the lysosomes themselves, causing the cell to die. As a result, lysosomes are referred to as the cell's "Suicide Bags."

Other options:

• a) Mitochondria are responsible for energy production, not waste disposal.
• b) Golgi bodies are involved in processing and packaging, not waste disposal.
• c) The cell membrane is a boundary structure; it does not perform digestion.

Ans. (a) Smooth Endoplasmic Reticulum

Explanation: Ribosomes are not seen in the smooth endoplasmic reticulum. Smooth endoplasmic reticulum takes part in the formation of phospholipids, which are the main lipids in cell membranes and are required for metabolism. The smooth endoplasmic reticulum stores and releases calcium ions. The neurological and musculoskeletal systems benefit greatly from these.

Other options:

• b) The cytoplasm is a cellular fluid, not directly involved in phospholipid synthesis.
• c) Mitochondria primarily produce energy and are not directly involved in phospholipid synthesis.
• d) While the endoplasmic reticulum is involved, it's specifically the smooth endoplasmic reticulum.