Genetics: Linkage Problem #2: Map Distance, Coefficient of Coincidence, and Interference

This video tutorial covers solving a linkage problem in genetics by finding map distances between genes, identifying the gene in the middle, and calculating the coefficient of coincidence and interference. The tutorial includes steps to identify parentals and crossovers, determine gene order, and compute gene distances in centimorgans. It concludes with calculating the coefficient of coincidence and interference, providing a comprehensive understanding of the genetic linkage analysis process.

What is the first step in solving a linkage problem in genetics?

• Identifying the gene in the middle

• Determining the total number of cases

• Finding the map distances between genes

• Calculating the interference

How can you identify the parentals in a genetic linkage problem?

• By finding the two with the least occurrences

• By finding the two with the most occurrences

• By looking for the ones with the most crossovers

• By identifying the ones with the least crossovers

What is the general rule for determining the gene in the middle?

• The gene that is not involved in any crossover

• The gene that changes in one double crossover and stays the same in the other

• The gene that stays the same in both double crossovers

• The gene that changes in both double crossovers

What is the unit used to express gene distances?

• Kilogram

• Centimorgan

• Molar

• Meter

How do you calculate the total distance between two genes?

• By adding the distances between the genes

• By multiplying the distances of the other genes

• By subtracting the distances of the other genes

• By dividing the distances between the genes

What is the formula for calculating the coefficient of coincidence?

• Total number of cases divided by double crossovers

• Single crossovers divided by the product of two distances and the total

• Double crossovers divided by the product of two distances and the total

• Double crossovers multiplied by the product of two distances

What does the interference value indicate in genetic linkage analysis?

• The likelihood of a single crossover

• The likelihood of a double crossover

• The degree to which one crossover interferes with another

• The total number of crossovers

What is the significance of a coefficient of coincidence value of 1?

• Complete interference between crossovers

• No crossovers occurred

• No interference between crossovers

• Partial interference between crossovers

Which of the following is NOT a step in solving a linkage problem?

• Identifying parentals

• Calculating gene distances

• Determining the gene in the middle

• Measuring the weight of the genes

What is the purpose of calculating the coefficient of coincidence?

• To measure the actual frequency of double crossovers

• To calculate the total number of crossovers

• To find the distance between genes

• To determine the total number of genes