Alevels Biology MCQ Quiz

Diffusion is the process in which molecules or particles move from an area of higher concentration to an area of lower concentration. This movement occurs naturally and does not require any energy input. Therefore, diffusion is the correct answer as it is the only process listed that does not require energy. Endocytosis, exocytosis, and pinocytosis are all active processes that involve the use of energy to transport substances across cell membranes.

Mitochondria support active transport. Active transport is the movement of molecules across a cell membrane against their concentration gradient, requiring energy. Mitochondria are the powerhouses of the cell, producing ATP, which is the energy currency of the cell. They provide the necessary energy for active transport processes to occur, such as the pumping of ions or the uptake of nutrients.

Resolution refers to the ability to distinguish between two close objects. It is a measure of the level of detail that can be seen in an image or displayed on a screen. A higher resolution means that smaller details can be distinguished, while a lower resolution may result in blurry or pixelated images where close objects merge together. Therefore, the correct answer is the "ability to distinguish between two close objects."

Water has a unique property where its density increases as it cools down until it reaches 4 degrees Celsius. As the temperature drops below 4 degrees Celsius, water molecules start to form a lattice-like structure, causing the density to decrease. This property is crucial for the survival of aquatic organisms during winter. When the frozen lake warms up, the ice starts to melt, and the water molecules rearrange themselves, resulting in water with a density higher than the surrounding water. This causes the nutrient-rich water at the bottom of the lake to rise to the surface, providing essential minerals for the ecosystem.

Ribosomes are the common feature in both prokaryotes and eukaryotes. Ribosomes are responsible for protein synthesis in cells. They are composed of RNA and protein molecules and are found in the cytoplasm of both prokaryotic and eukaryotic cells. While there are differences in the structure and organization of ribosomes between prokaryotes and eukaryotes, they both play a crucial role in protein production. Therefore, ribosomes are the correct answer as they are shared by both types of cells.

The tertiary structure of a protein refers to its three-dimensional arrangement, which is crucial for its function. One of the key features of this structure is the presence of hydrophilic and hydrophobic regions. These regions determine how the protein interacts with its environment, as hydrophilic regions tend to be exposed to water while hydrophobic regions are buried within the protein. This arrangement allows the protein to fold into a compact and stable shape, enabling it to perform its specific biological functions effectively.