AP BIOLOGY

Detailed explanation-1: -Animals take in oxygen through the lungs by internal and cellular respiration. It takes place inside the animal body and releases carbon dioxide. Plants photosynthesize their glucose. Animals obtain their glucose by the breakdown of carbohydrate molecules.

Detailed explanation-2: -Remember that one of the inputs to cellular respiration is carbohydrate, specifically glucose. Plants form glucose by photosynthesis and animals get glucose by breaking down the food they eat. During cellular respiration, glucose combines with oxygen to release energy and to form carbon dioxide and water.

Detailed explanation-3: -During photosynthesis, plants take in carbon dioxide (CO2) and water (H2O) from the air and soil. Within the plant cell, the water is oxidized, meaning it loses electrons, while the carbon dioxide is reduced, meaning it gains electrons. This transforms the water into oxygen and the carbon dioxide into glucose.

Detailed explanation-4: -Animals obtain energy from the food they consume, using that energy to maintain body temperature and perform other metabolic functions. Glucose, found in the food animals eat, is broken down during the process of cellular respiration into an energy source called ATP.

Detailed explanation-5: -Remember, all animal cells need oxygen. Oxygen which enters the animal’s body through its respiratory system (lungs, gills, skin, or exoskeleton) is carried by its transport system (blood for many animals to every animal cell.