Cell Quiz: The Fundamental Unit Of Life!

Plant cells have a rigid cell wall made of cellulose that provides structural support and protection. Animal cells, on the other hand, do not have cell walls; they only have a cell membrane. The other statements are incorrect:

Plant cells do have vacuoles, often large central vacuoles, while animal cells may have small vacuoles.

Plant cells have both cell walls and cell membranes, while animal cells have only cell membranes.

Plant cells have plastids (such as chloroplasts), which are typically not found in animal cells.

Robert Hooke is credited with coining the term "cell" to describe the basic unit of life. He observed cork under a microscope and noticed small compartments that resembled the cells of a monastery, which led him to name them cells. This discovery revolutionized the understanding of biology and laid the foundation for the cell theory.

Mitochondria are often referred to as the "power house of the cell" because they are responsible for generating energy in the form of ATP molecules. Through the process of respiration, mitochondria oxidize carbohydrates and fats to produce carbon dioxide, water, and a large amount of energy. This energy is then stored in ATP molecules, which can be used by the cell for various metabolic activities. Therefore, the term "power house of the cell" accurately describes the role of mitochondria in energy production and utilization.

The most appropriate answer for Rahul's question is "So that the vegetables may lose all the water by diffusion and evaporation and become dry." This answer explains that by putting the salted vegetables in the sun, the water content in the vegetables will evaporate, resulting in the vegetables becoming dry. This is an important step in making pickle as it helps in preserving the vegetables for a longer period of time.

The correct answer is the first option, "Movement of water molecules from a region of higher concentration to a region of lower concentration through a semipermeable membrane." This is the correct definition of osmosis, as it describes the movement of water molecules across a semipermeable membrane in response to a concentration gradient. The other options either describe the movement of solvent molecules or the movement of solute molecules, which are not accurate definitions of osmosis.

The endoplasmic reticulum is responsible for the synthesis and modification of proteins and lipids, which are essential components of the cell membrane. This organelle has a network of interconnected membranes where these molecules are produced and processed before being transported to their final destination. The Golgi apparatus also plays a role in modifying and packaging these molecules, but it does not directly manufacture them. Mitochondria and peroxisomes are involved in energy production and metabolism, respectively, and are not primarily responsible for building the cell membrane.

When the concentration of water molecules in the surrounding medium is higher than the concentration of water molecules in the cell, water will move into the cell through osmosis. This influx of water causes the cell to swell up.

The color change in fruit, when it ripens, is due to the transformation of chloroplasts into chromoplasts. Chloroplasts are responsible for the green color in unripe fruits, as they contain chlorophyll. However, during the ripening process, Chloroplasts start to break down and are converted into chromoplasts. Chromoplasts contain pigments such as carotenoids, which give fruits their vibrant colors, such as red, orange, or yellow. Therefore, the change from chloroplasts to chromoplasts is the reason behind the color change in ripening fruits.

The endoplasmic reticulum is a membranous network that connects the outer membrane of the nucleus to the plasma membrane, allowing for the transport of materials between various regions in the cytoplasm. It also serves as a transport channel for proteins between the nucleus and cytoplasm, and it can be the site of some biochemical activities of the cell. However, it is not involved in energy generation.

The correct order is A - Nucleolus, B - Chromatin, C - Nuclear membrane, D - Nucleoplasm. The nucleolus is responsible for producing ribosomes, which are essential for protein synthesis. Chromatin is the material that makes up the chromosomes and contains DNA. The nuclear membrane acts as a barrier, controlling the movement of substances in and out of the nucleus. The nucleoplasm is the fluid inside the nucleus that contains various components necessary for cellular processes.

The correct answer is "Plasma membranes contain chitin sugar in plants." This option does not belong to the process of osmosis because it refers to the composition of plasma membranes in plants, specifically mentioning the presence of chitin sugar. However, osmosis is a process that involves the movement of molecules of a solvent through a semipermeable membrane, and the composition of the membrane is not relevant to the definition of osmosis.

Plasmolysis is the process in which the cytoplasm of a plant cell shrinks due to the loss of water when placed in a hypertonic (concentrated) solution. The hypertonic solution has a higher solute concentration than the cell, causing water to move out of the cell through osmosis. As a result, the cytoplasm shrinks away from the cell wall. This process does not involve the breakdown of the plasma membrane or the shrinkage of nucleoplasm.

The statement "Cytoplasm is also known as protoplasm" is incorrect. Cytoplasm and protoplasm are two different terms. Cytoplasm refers to the jelly-like substance that fills the cell and contains various organelles, while protoplasm refers to the entire living content of a cell, including the cytoplasm and the nucleus.

The vacuole is not involved in the process of cell division, which is primarily regulated by the nucleus and other cellular structures. The vacuole plays a role in storing metabolic by-products, providing turgidity and rigidity to the cell, and maintaining osmotic pressure.

The phenomenon due to which the kidney beans were swollen is known as osmosis. Osmosis is the movement of water molecules from an area of lower solute concentration to an area of higher solute concentration through a semi-permeable membrane. In this case, the kidney beans absorbed water from the container, causing them to swell. Endosmosis is a specific type of osmosis where water moves into a cell or a structure. Therefore, (iii) is correct.