Skip to content


Choose a Chapter below or view the Sitemap

Unit 1:
Ch. 1
Ch. 2
Ch. 3
Interlude A
Unit 2:
Ch. 4
Ch. 5
Ch. 6
Ch. 7
Ch. 8
Ch. 9
Interlude B
Unit 3:
Ch. 10
Ch. 11
Ch. 12
Ch. 13
Ch. 14
Ch. 15
Interlude C
Unit 4:
Ch. 16
Ch. 17
Ch. 18
Ch. 19
Interlude D
Unit 5:
Ch. 20
Ch. 21
Ch. 22
Ch. 23
Ch. 24
Ch. 25
Ch. 26
Ch. 27
Ch. 28
Ch. 29
Ch. 30
Interlude E
Unit 6:
Ch. 31
Ch. 32
Interlude F
Unit 7:
Ch. 33
Ch. 34
Ch. 35
Ch. 36
Ch. 37
Ch. 38
Interlude G
The audio glossary requires the latest Flash plug-in.

Choose a letter below. Then, click the play button next to a term to hear the audio pronunciation.

  • X-linked: See sex-linked.
  • xylem: A tissue composed of dead cells through which a plant transports mineral nutrients and water from the soil to the leaves. Compare phloem.

Chapter Menu

Other Resources

Norton Gradebook

Instructors now have an easy way to collect students’ online quizzes with the Norton Gradebook without flooding their inboxes with e-mails.

Students can track their online quiz scores by setting up their own Student Gradebook.