Question

for the two graphs that are included, underneath each, give a description of the optimum zone, the zones of physiological stress and the zones of intolerance. barnacles are invertebrates that often live in areas affected by tides. they live attached to objects such as rocks and filter food from the water. as tides rise and fall, barnacles are often left exposed, above the water, for extended periods of time. if the barnacles are out of the water for too long (right side of the graph), this can lead to desiccation, which means that the barnacles are drying out, eventually causing them to die. tolerance curve for barnacles — vertical position as limiting factor (population size with stress and intolerance zones)

Explanation:

The optimum zone is where barnacle population size is highest, indicating ideal conditions. Physiological stress zones are areas where population size starts to decline, showing sub - optimal conditions that cause stress. Zones of intolerance are where the population size drops to near zero, meaning conditions are too harsh for barnacles to survive. For the given tolerance curve of barnacles with vertical position as a limiting factor, the optimum zone is likely around the middle range of centimeters above low tide (e.g., around 50 - 75 cm) where the population size is at its peak. Physiological stress zones would be on either side of the optimum zone, say from around 25 - 50 cm and 75 - 100 cm above low tide where the population size is decreasing. Zones of intolerance are at the extreme ends, below 25 cm and above 100 cm above low tide where the population size is very low.

Answer:

Optimum zone: Middle range of vertical positions (around 50 - 75 cm above low tide) where population size is highest. Physiological stress zones: On either side of the optimum zone (25 - 50 cm and 75 - 100 cm above low tide) where population size is decreasing. Zones of intolerance: Extreme ends (below 25 cm and above 100 cm above low tide) where population size is near zero.