Lesson Plans

Biology 5th Edition ©1999

by Campbell, Reece, Mitchell

Week 9: Chromosomal and Molecular Basis of Inheritance

Chapter 13: Meiosis and Sexual Life Cycles
Chapter 14: Mendel and the Gene Idea

College Board Performance Objectives:

• Explain how the structures of nucleic acids relate to their function of storage of information.
• Explain how linked genes tend to be inherited together.
• Describe how independent assortment of chromosomes and crossing over produce genetic recombinants.
• Explain how genetics use recombination data to map a chromosome's genetic loci.
• Explain how sex-linked genes have a unique pattern of inheritance.
• Explain the evidence that Watson and Crick used to build the DNA model.

College Board Lab Objectives:

Suggested Laboratory Experiments:

Resources:

• Chapter 13: Meiosis and Sexual Life Cycles, pp. 226–238
• Chapter 14: Mendel and the Gene Idea, pp. 239–260
• Instructor's Guide, pp. 201–229
• Student Study Guide, pp. 103–117
• Test Bank, pp. 171–194
• Lab Manual: none
• CD-ROM: Chapters 15 and 16 include narrated presentations, activities, and links to the Internet.

Pacing Guide:

• Chromosomal Basis of Inheritance—2.5 days
  Make a large model of a homologous pair of chromosomes with red and pink clay or snap beads. Place the trait for black body as a gene using blue clay on each of the chromosomes. Place another gene for vestigial wings by making a gene of yellow clay on each chromosome. Use Figure 15.5 as a guide. Have the students allow crossing over to produce recombinants. Then make two homologous pairs of chromosomes and place the blue gene for black body on one pair and the yellow gene for vestigial wings on another pair. Ask them why crossing over can not occur. They should conclude that crossing over can only occur between homologous chromosomes. There is no recombination of genes on nonhomologous chromosomes.
• The Molecular Basis of Inheritance—2.5 days
  Analyzing the DNA model and correlating the data that the various scientists collected will help students see the process of science that allowed for the discovery of the model. The FruitLoops^TM activity from Week 10 includes a replication exercise. This might be a good activity to do with this chapter and only review replication in Week 10 when transcription and translation are studied.

Key Words:

Suggested Exercises:
Critical thinking questions and end-of-chapter activities are included in these exercises.

1. Genetic Problems, pp. 276–277 #1–4
2. Challenge Questions, p. 293 #1–3
3. Science, Technology, and Society, p. 277 #1 and p. 293 #1–4
4. The following activity helps students see that the X chromosome from the mother transmits sex-linked diseases to their sons. If the great-grandfather was colorblind, and he was the only person in the family that was colorblind until the great-grandson was born, how was the trait inherited by the grandson? They should reason that the grandfather passed the X chromosome with the trait to his daughter and that made her a carrier. She passed the colorblind X chromosome to her daughter who is the great-grandson's mother, and she passes her X chromosome with the colorblind trait to the great-grandson.
5. Explain Griffith's experiment by using ping-pong balls for smooth Streptococcus pneumoniae cells and tennis balls for rough cells. To make heat killed smooth, crush some ping-pong balls. Emphasize that the DNA from the heat-treated rough cells transformed the smooth cells, but that Griffith was unsure of what exactly caused the transformation. Hershey and Chase were able to determine what caused the transformation.
6. Assembling small DNA models is a good activity to help student focus on the structure and function of DNA.

Troubleshooting Tips/Error Traps: