Biological responses refer to the reactions of living organisms to various stimuli in their environment. These responses can be physical, such as changes in heart rate or hormone levels, or behavioral, like fleeing from danger or seeking food. They help organisms adapt to their surroundings and maintain homeostasis, which is the balance necessary for survival. These responses are often triggered by external factors, such as temperature changes, light, or the presence of predators. For example, when humans feel cold, their bodies respond by shivering to generate heat. Similarly, plants may respond to sunlight by growing towards it, a process known as phototropism.