The arteries in the bottlenose dolphin that deliver blood to the flippers are enclosed by veins that carry blood back to the rest of the body. Outline how this blood-vessel arrangement helps conserve body heat.
After a dolphin has exercised for a long time, it may need to get rid of extra heat. Unlike humans, dolphins do not sweat. Suggest how a dolphin may lose excess heat.
Describe the patterns shown in Fig. 6.2.
The mean concentration of insulin in the blood changes with time in dolphins that were fed fish containing $11\ \text{g}$ of glucose per $\text{kg}$ of fish. Calculate the rate of change in the mean concentration of insulin in this group of dolphins from the time they were fed until the concentration reaches its maximum. Show your working.
Blood glucose concentration is regulated by negative feedback. Explain what is meant by negative feedback.