Name
PD
27.2 Respiration
Lesson Objectives
Describe the characteristics of respiratory structures that all animals share.
Explain how aquatic animals breathe.
Identify the respiratory structures that enable land animals to breathe.
Gas Exchange
For Questions 1–5, write True if the statement is true. If the statement is false, change the
underlined word or words to make the statement true.
1. In respiratory systems, gas exchange occurs through active diffusion.
2. Substances diffuse from an area of higher concentration to an area of lower
concentration.
3. Gases diffuse most efficiently across thin, dry surfaces.
4. Respiratory structures have a selectively permeable membrane.
5. Respiratory structures maintain a difference in the relative concentrations of
oxygen and nitrogen on either side of the membrane.
6. Respiratory organs have large surface areas. How is this an advantage to an animal?
7. Respiratory surfaces are moist. How does this enable respiration to take place?
Respiratory Surfaces of Aquatic Animals
8. Complete the flowchart that describes the path of water as it moves through fish.
Water flows in through the fish’s
water across the
.
, where muscles pump the
As water passes over the gill filaments, the filaments absorb
from water and release.
Water and carbon dioxide are pumped out behind the
.
Respiratory Surfaces of Terrestrial Animals
11. Describe the basic process of breathing among land vertebrates.
12. Why are the lungs of birds more efficient than those of most other animals?
27.3 Circulation
Lesson Objectives
Compare open and closed circulatory systems.
Compare patterns of circulation in vertebrates.
2.
THINK VISUALLY Label the structures shown on each organism. Then write on the
line below the organism whether the organism has an open or a closed circulatory system.
Single- and Double-Loop Circulation
3. Identify where the blood is carried in each loop of a double-loop circulatory system.
4. Why is a four-chambered heart sometimes described as a double pump?
5. What is the difference between a reptilian heart and an amphibian heart?
For Questions 6–9, complete each statement by writing the correct word or words.
6. In most vertebrates with gills, the heart consists of
chambers.
7. The heart chamber that pumps blood out of the heart is called the
8. Most vertebrates that use gills for respiration have a
loop circulatory system.
9. In a double-loop system, oxygen-poor blood from the heart is carried to the
27.4 Excretion
Lesson Objectives
Describe the methods animals use to manage nitrogenous wastes.
Explain how aquatic animals eliminate wastes.
Explain how land animals eliminate wastes.
The Ammonia Problem
1. Why does ammonia build up in organisms?
2. Why is ammonia a problem in the body of an animal?
.
3. Complete the concept map.
Ways to Store Nitrogenous Waste
Ammonia
is converted into
by
by
Excretion in Aquatic Animals
4. How do many freshwater invertebrates rid their bodies of ammonia?
5. Describe how flatworms maintain water balance.
6. Why do freshwater fishes typically have very dilute urine and marine fishes have very
concentrated urine?
For Questions 7–8, write the letter of the correct answer on the line at the left.
7. Marine organisms tend to lose water to their surroundings because
A. their bodies are less salty than the water they live in.
B. their bodies are more salty than the water they live in.
C. their cells actively pump water across their membranes.
D. their cells actively pump ammonia across their membranes.
8. Which of the following structures helps remove excess water from an organism’s
body?
A. a gill
C. a flame cell
B. a ventricle
D. an operculum
For Questions 10–12, complete each statement by writing the correct word or words.
10. In terrestrial vertebrates, excretion is carried out mostly by the
11. In mammals, urea is excreted from the body in a liquid known as
12. Most vertebrate kidneys cannot excrete concentrated
.
.
.