General Lesson Planning Format

LESSON TITLE: Pedigrees and Sickle-cell Anemia TIME REQUIRED: 100 min

SUBJECT / STRAND: SBI 3U, Genetic Continuity GRADE: 11U

EXPECTATIONS COVERED: ASSESSMENT: Overall Expectation: Formative - demonstrate an understanding of the necessity of meiosis and describe the importance of genes in transmitting hereditary characteristics according to Mendel’s model of inheritance Specific Expectations: -predict the outcome of various genetic crosses. -describe genetic disorders (e.g., Down syndrome, cystic fibrosis,muscular dystrophy, fragile X syndrome) in terms of the chromosomes affected, physical effects, and BACKGROUND KNOWLEDGE: SAFETY CONCERNS? -genetics terms: chromosome, DNA None -processes: mitosis, meiosis

LESSON DESCRIPTION: - (40 min) Introduction to Pedigrees, Pedigree analysis - (20 min) Case Study: A Mysterys O Students work in groups to solve genetics and pedigree problem - (40 min) Sickle-cell Anemia O Pedigree work sheet (part of test review)

REFLECTION:

Case Study: A Mystery

There are four different ABO blood types as shown in Table 2. The Phenotypes Genotypes alleles for blood types A and B are codominant but are dominant type A IAIA, IAIO over the allele for type O. The rhesus factor is a blood factor that type B IBIB, IBIO is regulated by a gene. The Rh-positive allele is dominant over the type AB IAIB type O IOIO Rh-negative allele. In this activity, you will solve a murder mystery using genetics.

Evidence: As a bolt of lightning flashed above Black Mourning Castle, a scream echoed from the den of Lord Hooke. When the upstairs maid peered through the door, a freckled arm reached for her neck. Quickly, the maid bolted from the doorway, locked herself in the library, and telephoned the police. Inspector Holmes arrived to find a frightened maid and the dead body of Lord Hooke. Apparently, the lord had been strangled. The inspector quickly gathered evidence. He noted blood on a letter opener, even though Lord Hooke did not have any cuts or abrasions. The blood sample proved to be type O, Rh-negative. The quick-thinking inspector phoned the family doctor for each family member’s medical history. The pedigree shown includes the relatives who were in the castle at the time of Lord Hooke’s murder.

The inspector gathered the information in Table 3.Some of the family members were deeply tanned, so the inspector found it difficult to determine whether or not freckles were present on their arms. Note: having freckles is an inherited trait and the allele for freckles is dominant over the allele for no freckles.

The crafty inspector drew the family close together and, while puffing on his pipe, indicated that he had found the murderer. He explained that one of the heirs to the fortune was not Lord Hooke’s biological child. The inspector believed that the child committed the murder.

Analysis :

(a) Who was the murderer? State the reasons for your answer.

(b) Describe the procedure you followed to obtain your answer.

(c) How did the inspector eliminate the other family members?

SBI 3U – Genetics Name: ______

Hemophilia Pedigree – Queen Victoria SBI 3U – Genetics Name: ______1. How many generations are represented in the pedigree? ______

2. In generation I, which parent is HETEROZYGOUS for the recessive allele? ______

3. Which individual (represented by the #) in generation II marries a spouse who is HOMOZYGOUS DOMINANT? ______

4. Which generation contains the most carriers?______

5. Can 2 carriers produce an individual with Sickle-Cell Anemia? Is there evidence of this in the pedigree? Explain. ______

______

6. Can a normal HOMOZYGOUS individual produce offspring with Sickle-Cell Anemia? Is there evidence of this in the pedigree? Explain. ______

______

7. Which parents produce 2 different sex children with Sickle-Cell Anemia? (Use generation and individual – e.g. I-1) ______1. Tay-Sachs disease is a fatal genetic disorder caused by a recessive allele. The pedigree chart below shows the appears of the disease in three generations of a family. Tell the genotype or possible genotypes of each member of the family. Be sure to define your variables.

Key: 1 2 (from a family with no history of = Normal male TaySachs) = Tay-Sachs male

= Normal female 3 4 5 6 7

= Tay-Sachs female

8 9 10

2. Draw a pedigree chart for the family described below and use the chart to determine the genotype or possible genotypes of each member of the family. Be sure to define your variables.

In humans, having freckles is dominant over not having them. Both Mr. And Mrs. Chambers have freckles. Of their three children, Robin and Daniel have freckles but Alex does not. Robin marries Stephen, who does not have freckles. They have two children, Kevin and Beth, who do not have freckles. Daniel marries Diane who also has freckles. They have one son, Phillip, who also has freckles. Alex marries Mary, who has freckles. They have one daughter, Norma, who does not have freckles.

PEDIGREES: BASIC SYMBOLS Fraternal Twins Identical Twins