SECTION
26.1
AMNIOTES
Study Guide
KEY CONCEPT
Reptiles, birds, and mammals are amniotes.
MAIN IDEA:
VOCABULARY
pulmonary circuit
systemic circuit
ectotherm
endotherm
Amniote embryos develop in a fluid-filled sac.
1. Why is it important that an amniotic egg shell is semi-permeable?
2. Complete the following chart with a description of each type of membrane found within
an amniotic egg. Use Figure 26.1 to help you.
Membrane
Description
allantois
amnion
yolk sac
3. Why was the development of the amniotic egg an important adaptation for amniotes?
MAIN IDEA:
Anatomy and circulation differ among amniotes.
4. What are three characteristics of a sprawling stance?
CHAPTER 26
A Closer Look at Amniotes
Copyright by McDougal Littell, a division of Houghton Mifflin Company
chorion
5. What are three characteristics of an upright stance?
6. What is the difference between the pulmonary circuit and the systemic circuit?
Unit 8 Resource Book
McDougal Littell Biology
Study Guide
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STUDY GUIDE, CONTINUED
7. Use the Venn diagram below to list the differences between the circulatory system of a
reptile and the circulatory system of a mammal.
Reptile Circulatory
System
MAIN IDEA:
Both
Mammal Circulatory
System
Amniotes can be ectothermic or endothermic.
8. What is the difference between an ectotherm and an endotherm?
9. garter snake
10. peregrine falcon
11. your biology teacher
Vocabulary Check
CHAPTER 26
A Closer Look at Amniotes
12. What word in the term systemic can help you to remember the difference between the
96
systemic circuit and the pulmonary circuit? Explain why.
13. The prefix endo- means inner and the prefix ecto- means outer. Relate these two
meanings to the definition of endotherm and ectotherm.
Study Guide
Unit 8 Resource Book
McDougal Littell Biology
Copyright © McDougal Littell/Houghton Mifflin Company.
For each type of amniote, indicate whether it is an ectotherm or an endotherm.