Final answer:
As organisms increase in size, their surface area-to-volume ratio decreases. Larger organisms account for this by becoming multicellular and developing specialized organ systems. Metabolic rate tends to decrease as body size increases, but larger organisms still have higher absolute metabolic rates.
Step-by-step explanation:
As organisms increase in size, their surface area-to-volume ratio decreases. This means that the surface area of the organism's body increases at a slower rate compared to its volume. This can lead to a problem as the organism gets larger because it may not have enough surface area to support its increasing volume.
To account for this problem, organisms of larger size have developed various adaptations. One adaptation is to become multicellular, allowing for specialization of cells and organs. This increases the overall surface area of the organism's body. Another adaptation is the development of organ systems, such as circulatory and respiratory systems, that efficiently transport nutrients, remove waste, and provide oxygen. These adaptations help maintain a sufficient surface area-to-volume ratio in larger organisms.
The metabolic rate of an organism tends to decrease as its body size increases. This is because larger organisms have a lower surface area-to-volume ratio, which reduces the efficiency of nutrient exchange and waste removal. Additionally, larger organisms often have lower resting metabolic rates compared to smaller organisms. However, larger organisms also tend to have higher absolute metabolic rates due to their larger overall size. These variations in metabolic rate with body size can be influenced by factors such as environmental conditions, activity level, and evolutionary adaptations.