DNA Bioscience Problem Solving Workbook

The DNA Bioscience problem solving workbook is assembled to educate DNA testing consumers about the different ways DNA testing is used to establish paternity, provide identification, and solve crimes.

The first problem in this workbook demonstrates how the DNA profiles of a mother and father can be used to determine who their child is. The second problem demonstrates how DNA profiles can be used to solve a crime. The third problem is used to help people understand what things contain DNA, and what things do not.

The answers are located below each problem.

Which child (in Figure 2) belongs to the parents (in Figure 1)?

Did you know that everyone has a unique DNA profile? By looking at several different locations on your DNA, you can see a pattern that makes you different from everyone else. Furthermore, you get half your DNA from each of your parents.

By looking at the DNA profiles below, can you determine which child (in Figure 2) belongs to the mother and father (in Figure 1)?

Figure 1: The parents' DNA profiles

Mother's DNA Locus 1: 10 12 Locus 2: 12 16 Locus 3: 24 28 Locus 4: 16 19

Father's DNA Locus 1: 11 15 Locus 2: 10 14 Locus 3: 25 27 Locus 4: 15 19

Figure 2: The DNA profiles of three children

Christina's DNA Locus 1: 10 15 Locus 2: 12 14 Locus 3: 24 27 Locus 4: 16 19

Katie's DNA Locus 1: 11 14 Locus 2: 10 15 Locus 3: 25 29 Locus 4: 16 17

Billy's DNA Locus 1: 14 16 Locus 2: 11 17 Locus 3: 23 29 Locus 4: 17 20

Answer: The mother and father are Christina’s parents. Billy and Katie have different parents. At Locus 1, Christina got the 10 from her mother and the 15 from her father. At the other Loci, can you determine which markers Christina got from her mother and which she got from her father?

Whose DNA is on the biscuit tin?

Since everyone has a unique DNA profile, when people touch things they can leave trace evidence of their DNA that can link them to the location. DNA evidence can be used to solve crimes by placing someone at the scene of a crime.

For example, after some biscuits were taken from a biscuit tin, the biscuit tin was tested for DNA. Below you can see the DNA profile that was found on the biscuit tin. Billy, Christina and Katie all say that they have never touched the biscuit tin.

By comparing the DNA profile on the biscuit tin (Figure 3) with the DNA profiles for Billy, Christina, and Katie (Figure 4), can you tell who touched the biscuit tin?

Figure 3: The DNA profile found on the biscuit tin

DNA on the biscuit tin
Locus 1:	11	14
Locus 2:	10	15
Locus 3:	25	29
Locus 4:	16	17

Figure 4: The DNA profiles of three children

Christina's DNA Locus 1: 10 15 Locus 2: 12 14 Locus 3: 24 27 Locus 4: 16 19

Katie's DNA Locus 1: 11 14 Locus 2: 10 15 Locus 3: 25 29 Locus 4: 16 17

Billy's DNA Locus 1: 14 16 Locus 2: 11 17 Locus 3: 23 29 Locus 4: 17 20

Answer: Katie's DNA matches the DNA found on the biscuit tin.

Which items listed below contain DNA, and which do not?

Can you tell which of the following contain DNA and which do not? Remember: DNA is in all living things. (Hint: 9 of the items below have DNA, and 9 do not)

Answers: The cat, dog, tree, mouse, flower, fish, monkey, snake, and bug all contain DNA.