LS255 Practice Quiz: Ace Your Exam

Cells are the fundamental units that make up all living organisms. They contain the necessary components to carry out life processes.

Mitochondria produce ATP, the energy currency of the cell, and are therefore known as the powerhouse. Their role in energy production is critical for cell function.

Photosynthesis is the process by which plants convert light energy into chemical energy in the form of glucose. This process is fundamental for plant survival and supports life on Earth.

The cell membrane is primarily composed of a phospholipid bilayer, which forms a semi”permeable barrier. This structure is essential for maintaining the integrity and function of the cell.

DNA holds the genetic blueprint of an organism, dictating its traits and functions. It is essential for inheritance and controlling cellular activities.

ATP is mainly generated in the mitochondria via oxidative phosphorylation. This step is crucial for energy production during cellular respiration.

Crossing over occurs during meiosis when homologous chromosomes exchange segments of DNA. This recombination produces genetic variation among offspring.

Proteins function as enzymes due to their specific three-dimensional structures. Their catalytic activity accelerates biochemical reactions in the cell.

Ribosomes are the sites of protein synthesis, translating mRNA into polypeptide chains. They are essential for proper gene expression and cell function.

Mitosis is the process by which a cell divides to produce two genetically identical daughter cells. This form of cell division is key for growth and tissue repair.

The nucleus contains the majority of the cell's genetic material and controls gene expression. It plays a central role in regulating cellular activities.

Photosynthesis harnesses light energy to produce glucose and oxygen from carbon dioxide and water. This process is vital to life on Earth, supporting the energy needs of nearly all organisms.

Chlorophyll is the pigment that absorbs light energy, a crucial first step in photosynthesis. It is responsible for the green color of plants and initiates the energy conversion process.

ATP (adenosine triphosphate) is known as the energy currency of the cell, as it stores and transfers energy for various metabolic processes. Its high-energy bonds are essential for powering cellular functions.

Genetic variation provides the raw material for natural selection, enabling populations to adapt over time. This diversity is essential for evolution and the survival of species in changing environments.

The fluid mosaic model describes the cell membrane as a flexible bilayer with interspersed proteins. This structure creates regions that are hydrophilic and hydrophobic, allowing selective transport of molecules.

Osmosis is the diffusion of water through a semi-permeable membrane from an area of lower solute concentration to one of higher solute concentration. This process is essential for maintaining cell turgor and homeostasis.

DNA replication occurs during the S phase (Synthesis phase) of the cell cycle. This step is critical to ensure that each daughter cell receives an accurate copy of the genome.

The proton gradient generated in the electron transport chain powers ATP synthase via chemiosmosis. This gradient is essential for converting energy from electrons into the usable form of ATP.

Mutations are a source of genetic variation, providing new alleles that may be beneficial, neutral, or harmful. Natural selection acts on these variations, guiding the evolutionary process over time.