Twins
Fred & Rita talk about identical twins
Do you know the difference between identical & fraternal twins?
Fred and Rita are in the library. Fred has to do a class presentation on genetics and DNA that afternoon. He hasn’t done the work.
Fred: Looking at the textbook Let’s see if I understand this. Fraternal twins share only 50% of their genes.
Rita: Like any brother and sister. But identical twins have the same DNA because they come from the same split egg.
Fred: They are basically the same person.
Rita: Don’t be silly, Fred. No two people are exactly alike. We’re all different.
Fred: Even when the DNA is exactly the same?
Rita: That’s only until the egg divides. After there are tiny gene mutations. Anyway, genes don’t explain everything. My cousins are identical twins but we can always tell them apart.
Fred: How?
Rita: It’s hard to explain. There are little physical things. And they have different personalities
Fred: But what about that identical twin the police arrested in America? They had DNA evidence against him but - .
Rita: He accused his brother?
Fred: And his brother accused him! One was lying but they couldn’t prove it.
Rita: Because there DNA was exactly the same? They should have gone back to the old fashioned method.
Fred: What’s that?
Rita: Fingerprints. Everybody has a different fingerprint. She reads out this quotation
Download the Fred & Rita Teaching Pack for only £1.75
Fred: Looking at the textbook Let’s see if I understand this. Fraternal twins share only 50% of their genes.
Rita: Like any brother and sister. But identical twins have the same DNA because they come from the same split egg.
Fred: They are basically the same person.
Rita: Don’t be silly, Fred. No two people are exactly alike. We’re all different.
Fred: Even when the DNA is exactly the same?
Rita: That’s only until the egg divides. After there are tiny gene mutations. Anyway, genes don’t explain everything. My cousins are identical twins but we can always tell them apart.
Fred: How?
Rita: It’s hard to explain. There are little physical things. And they have different personalities
Fred: But what about that identical twin the police arrested in America? They had DNA evidence against him but - .
Rita: He accused his brother?
Fred: And his brother accused him! One was lying but they couldn’t prove it.
Rita: Because there DNA was exactly the same? They should have gone back to the old fashioned method.
Fred: What’s that?
Rita: Fingerprints. Everybody has a different fingerprint. She reads out this quotation
The pattern of our fingerprints is set up by our genes. Just like with other genes, though, the environment can change how we turn out.While you were growing inside of your mother, you touched the amniotic sac. When you touched it during weeks 6-13, the patterns of your fingerprints were changed. This is why identical twins have different fingerprints.
Download the Fred & Rita Teaching Pack for only £1.75
Quick Check
True or false
1. Fraternal twins are not identical.
2. Gene mutations create identical twins.
3. Every individual is different.
4. Fingerprints are affected by the environment.
5. Your fingerprint changes before you are born.
Identical Twins - Different Lives
Read about a recent 'wrong twin' murder case. Why 'identical twins genes are not identical'? How police might approach identical twin DNA problem
Download the Fred & Rita Teaching Pack for only £1.75
True or false
1. Fraternal twins are not identical.
2. Gene mutations create identical twins.
3. Every individual is different.
4. Fingerprints are affected by the environment.
5. Your fingerprint changes before you are born.
Identical Twins - Different Lives
Read about a recent 'wrong twin' murder case. Why 'identical twins genes are not identical'? How police might approach identical twin DNA problem
Download the Fred & Rita Teaching Pack for only £1.75
The complete Fred & Rita Teaching Pack is only £1.75
