Genetics Cognitive Tutor

The Carnegie Mellon Genetics Cognitive Tutor


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Each of the 7 modules shown below include:
• Written instruction on the related genetics
• Video instructions and written instructions on completing the problems
• Between 4 and 20 problems to solve
• Note: Students can complete each problem once

The tutor keeps track of student progress:
• Students work at their own pace.
• Students do not need to complete a module in one sitting.
• Students can log out at any time. When they log in again, the tutor starts them where they left off.

Each problem presents a family pedigree displaying a rare trait and asks the student to determine the dominance and linkage of the trait.

View Video of Pedigrees - Basic Analysis

Each problem describes three parents that are true breeding for a phenotypic trait. The student’s task is to determine the inheritance of the trait in each problem. The student performs three crosses on the parent strains along with intercrosses on the resulting F1 progeny and determines the genotypes of the true breeding strains along with the genotypes of all the F1 and F2 progeny.

View Video of Gene Interaction and Epistasis

Each problem presents a family pedigree displaying a rare trait and asks the student to determine: (1) the dominance and linkage of the trait; (2) the probability that various family members are carriers of an allele of the trait; (3) the probability that an unobserved family member will be affected by the trait.

View Video of Pedigrees - Carrier Probabilities

In each problem the student determines the order of three genes on a chromosome and the distances in centimorgans (cM) between the pairs of genes.

View Video of Three Factor Cross

Each problem asks the student to calculate whether a population is in Hardy-Weinberg equilibrium, by comparing observed and expected numbers of each genotype in the population.

View Video of Population Genetics - Equilibrium

Each problem describes selection pressures on genotype classes in a population and asks the student to calculate the impact of these pressures on genotype numbers in successive generations of the population.

View Video of Population Genetics - Departures

Each problem describes the regulatory system for synthesis of a protein. The student’s tasks are to (1) complete a summary description of the regulatory system (2) indicate how the presence or absence of the effector affects protein synthesis in the normally functioning system and in the presence of various mutations.

View Video of Gene Regulation

In each problem students design experiments to (1) determine the effector in the system, by manipulating the presence or absence of possible effectors, and (2) to determine, as far as possible, if the regulatory system is inducible or repressible; whether it is a positive or negative regulatory system; and the role of each of the three genes in the system. To draw these latter conclusions, students examine the impact of selectively knocking out one gene at a time and the impact of a plasmid functional copy of the gene.

In each problem students are given a set of unordered tetrads that result from a cross. In these problems, students classify the tetrad types; reason about the quantitative relationships among the tetrad types; draw qualitative linkage conclusions about the genes; and calculate the map distance between the genes.

In each problem, students are given the rate of occurrence for two traits in a population and are told whether a mother and father are affected by either trait. Students are asked to calculate the probability that either a son or daughter will be affected by both traits.

Some of these problems describe the functioning of two genes. Students summarize how the genes interact in words; indicate the phenotypes of the true-breeding genotypes; indicates the offspring genotypes and phenotypes that result from crossing two true-breeding strains and intercrossing the offspring; and finally the student describes in words how the genes interact to determine each phenoytpe.

In other problems, students are given the results of crossing true-breeding strains and intercrossing the offspring. Students summarize how the genes appear to interact in words; indicate the phenotypes of the true-breeding genotypes; and finally the student explains the F2 phenotypes, phenotype ratios, and genotypes in the given cross and describe how the genes interact to determine each phenotype.