Chapter 28.1, Problem 4MI

Summary Introduction

To define:

The given term “propulsion” to show its scientific meaning.

Introduction: Fishes are vertebrates that have characteristics allowing them to live and reproduce in water. The features of fishes provided the structural basis for the evolution of land animals. Important features of fishes include development of jaws, and in some fishes, lungs. Most fishes have jaws, paired fins, scales, gills and single loop blood circulation.

Answer to Problem 4MI

Propulsion is an act of moving forward by means of a force that causes motion.

Explanation of Solution

Paired fins are an important feature in fishes. A fin is a paddle shaped structure on a fish or any aquatic animal that help in maintaining balance, steering and in propulsion. Fishes are well adapted to swimming. Fins enable the fish to steer and maneuver in a variety of ways. Fishes move in water by contracting muscles on either side of their bodies. This causes the body of the fish to bend and move forward at an angle. This forward moving by a force is called propulsion. Some fast moving fish use only their tails to push forward through water.