Human Biology, 14 Edition

Published by McGraw-Hill Education
ISBN 10: 1-25924-574-8
ISBN 13: 978-1-25924-574-9

Chapter 21 - Assess - Page 475: 13

Answer

13. e. pleiotropy. Pleiotropy is the genetic phenomenon in which a gene at a single locus affects more than one trait (has several effects). Crohns disease, phenylketonuria (PKU), and systemic lupus erythematous (SLE) are pleitropic conditions.

Work Step by Step

Pleitropy should not be confused with polygenic inheritance: In pleiotropy a gene at a single locus is responsible for various phenotypic experessions. But in polygenic inheritance several genes at different loci contribute to the phenotype. Examples of polygenic expressions in humans are body height, skin color and blood pressure. Diseases like essential hypertension and pyloric stenosis are also polygenic conditions.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.