Living organisms share several key characteristics, such as the ability to grow, reproduce, respond to stimuli, metabolize, and maintain homeostasis. These functions are carried ou... Living organisms share several key characteristics, such as the ability to grow, reproduce, respond to stimuli, metabolize, and maintain homeostasis. These functions are carried out by cells, the basic units of life, which can be classified as prokaryotic or eukaryotic. Movement into and out of cells occurs through processes such as diffusion, osmosis, and active transport, allowing cells to maintain proper balance and function. Inside cells, biological molecules like carbohydrates, proteins, lipids, and nucleic acids are essential for structure, energy, and the transmission of genetic information. Enzymes play a crucial role by acting as catalysts for biochemical reactions, increasing the efficiency of processes like digestion and energy production. In plants, nutrition primarily occurs through photosynthesis, where they convert sunlight, carbon dioxide, and water into glucose and oxygen. Transport in plants is carried out by the xylem, which moves water and minerals from the roots to the leaves, and the phloem, which distributes food produced in the leaves to other parts of the plant. In animals, the circulatory system is responsible for transport, distributing oxygen, nutrients, and waste products throughout the body. Organisms face threats from diseases caused by pathogens, but their immune systems provide defense. In humans, the respiratory system facilitates gas exchange, allowing oxygen to enter the blood and carbon dioxide to be expelled. Respiration is the process by which cells generate energy, either aerobically (with oxygen) or anaerobically (without oxygen). Drugs can influence the body's functions, either helping treat illnesses or causing harm through misuse. Reproduction can be sexual or asexual, with humans relying on sexual reproduction involving sperm and egg cells. Organisms interact with their environments, and humans significantly impact ecosystems through activities such as deforestation and pollution, influencing biodiversity and ecosystem stability. Read more