Question

Chapter 21: Unifying Concepts of Animal Structure and Function 10. List three organ systems and their primary functions. Chapter Content: Exchanges with the External Environment Complete the following questions as you read the twenty-first chapter content-Exchanges with the External Environment: 1. The continuous exchange of chemicals and energy with your surroundings is referred to as an) 2. What is a major adaptation that complex animals, such as humans, have evolved to maximize exchange with the external environment? 3. Briefly explain why the hydra does not need a digestive, respiratory, and urinary system.

Answer 1

1. Law of thermodynamics

2. Homeostasisis the major adaptation that complex animals such as humans have evolved to maximize exchange with the external environment organisms must be able to adapt to a changing external and internal environment. Organisms have the ability to maintain a stable internal environment is known as homeostasis. However, homeostasis refers to the necessity of an organism to maintain constant or stable internal conditions.

3. Hydra does not have digestive, urinary and respiratory system because use their cell surface as a point of exchange with the outside environment.It also lacks specialized organs such as hearts and blood vessels, instead of using their skin as an exchange point for materials. This, however, limits the size an animal can attain. To become larger, they need specialized organs and organ systems.