b. Describe three external features of the dolphin that are adapted for marine life.

b) Here are three external features of the dolphin that are adapted for marine life:

1. Streamlined, fusiform body shape:

   • Adaptation: Dolphins have a torpedo-shaped body that tapers at both ends.
   • Explanation: This smooth, hydrodynamic shape significantly reduces drag and turbulence as the dolphin moves through water, allowing for efficient and fast swimming with minimal energy expenditure.

2. Flippers and a horizontal fluke:

   • Adaptation: The forelimbs are modified into paddle-like flippers, and the hind limbs are absent, replaced by a powerful, horizontal tail fin called a fluke.
   • Explanation: The flippers are used for steering, balance, and stability in the water. The large, muscular fluke moves up and down to provide the primary propulsion force for swimming.

3. Smooth, hairless skin:

   • Adaptation: Dolphins have very smooth skin with no fur or hair.
   • Explanation: This smooth surface further reduces friction and drag when swimming, enhancing their streamlined movement through water. It also helps in maintaining body temperature in water, often with a layer of blubber underneath for insulation.