This is a science activity for 9th grade biology students that builds on student knowledge of genetics (specifically basic Mendelian genetics) and probabilities by introducing the relationship that malaria and sickle-cell anemia have with each other. Students will watch a short 5 minute video explaining the link of sickle-cell and malaria. There will then be a short discussion clearing up any misconceptions or unclear areas.

This activity is conducted after the introductory lessons to Mendelian genetics have been taught. Students utilize what they have learned from prior lessons and connect it to a real-world occurrence involving the learned material. In this case, Mendelian genetics and how it ties into sickle-cell anemia, which in turn has a special relationship with malaria. They will expected to be familiar with and use Punnett squares and probabilities to complete a pedigree chart and determine whether a young couple who has sickle-cell in their family tree, should or should not reproduce.

This WebQuest s designed to engage students in a fun research activity to further master Mendelian genetics. Once the WebQuest is complete, the student groups will present the information they have found and persuade the young couple, using evidence found in the pedigree chart, whether or not they should conceive a child, and the risks of conceiving one.

The following standards, crosscutting concepts, and science and engineering practices are being addressed through this WebQuest:

NGSS Standard(s):

HS-LS3 Heredity: Inheritance and Variation of Traits

• LS3.A Inheritance of Traits: Each chromosome consists of a single very long DNA molecule, and each gene on the chromosome is a particular segment of that DNA. The instructions for forming species' characteristics are carried in DNA. All cells in an organism have the same genetic content, but the genes used (expressed) by the cell may be regulated in different ways.
• LS3.B Variation of Traits: Environmental factors also affect expression of traits, and hence affect the probability of occurrences of traits in a population. Thus the variation and distribution of traits observed depends on both genetic and environmental factors.

HS-LS4 Biological Evolution: Unity and Diversity

• LS4.C Adaptation: Evolution is a consequence of the interaction of four factors: (1) the potential for a species to increase in number, (2) the genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for an environment's limited supply of resources that individuals need in order to survive and reproduce, and (4) the ensuing proliferation of those organisms that are better able to survive and reproduce in that environment.

Crosscutting Concept(s):

• Patterns: If a person has sickle-cell anemia (s)he cannot have malaria, if a person has no sickle-cell genes (s)he is susceptible to malaria, and if a person has one sickle-cell gene (s)he cannot have malaria. There are also many patterns when observing pedigree charts.
  
• Cause and Effect: The genotype of an organism will explain a lot about the traits of that organism. In this case if a person is homozygous recessive then (s)he will suffer from sickle-cell, but will be resistant to malaria.
• Systems and System Models: In this lesson Punnett squares are used to model genotypes of a person.

Science and Engineering Practices:

• Developing and Using Models: Punnett Squares and pedigree charts will be used in our lesson to represent the possible genotypes of offspring and model a family history.
• Planning and Carrying Out Investigations: Students are asked to develop a family's pedigree chart and determine the likelihood of a couple having a child with sickle-cell.
• Using Mathematics and Computational Thinking: Mathematics is used throughout the lesson trying to figure out the probability of offspring having sickle-cell.
• Obtaining, Evaluating, and Communicating Information: The students have to take given information to create a pedigree chart and use that information to determine the likelihood the couple's children will have sickle-cell anemia and/or be susceptible to malaria.