Listen&Learn: Fingerprints

Learn why we have unique patterns on our fingers

Pre-listening vocabulary

• physical: relating to the body
• genetic: caused by DNA
• permanent: lasting forever
• identify: to find out who someone is
• accurate: correct
• proportions: the size of one thing in comparison to something else
• foolproof: always reliable, having no room for error

Listening activity

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Gapfill exercise

Unlike most physical features, fingerprints are not genetic. The patterns on our fingers develop in the womb, while is still growing. For this reason, no two people have the same fingerprints, even identical . The ridges of a fingerprint are the same through multiple of skin. This is why fingerprints stay the same after cuts or scrapes heal. To permanently change your fingerprint, you would need to destroy all of the skin’s outer layers and damage the inner layer, which is called the dermis. Since the early 20th century, many law enforcement agencies have used fingerprints to identify people. They are more accurate than earlier identification techniques, such as measuring proportions. However, fingerprints are not a foolproof way to find someone. Some diseases and medications can cause people to lose their fingerprints. A very small percentage of people are even born without them. This can make it difficult to get documents, enter different countries, and apply for certain jobs.

Comprehension questions

See answers below

1. Fingerprints develop
   a. when DNA first forms
   b. in the womb, while skin is still growing
   c. a few days after birth
   
2. To change your fingerprint, you would need to damage a layer of skin called
   a. the epidermis
   b. the dermis
   c. the hypodermis
   
3. A very small percentage of people
   a. have matching fingerprints
   b. have fingerprints that change naturally
   c. have no fingerprints

Discussion/essay questions

1. Many cell phones now allow people to use their fingerprints to secure their personal information. Some people find this concerning. Unlike a password, it is very difficult to change your fingerprint. Do you think it is a good idea to secure your information with a fingerprint? Why or why not?

Transcript

Unlike most physical features, fingerprints are not genetic. The patterns on our fingers develop in the womb, while skin is still growing. For this reason, no two people have the same fingerprints, even identical twins. The ridges of a fingerprint are the same through multiple layers of skin. This is why fingerprints stay the same after cuts or scrapes heal. To permanently change your fingerprint, you would need to destroy all of the skin’s outer layers and damage the inner layer, which is called the dermis. Since the early 20th century, many law enforcement agencies have used fingerprints to identify people. They are more accurate than earlier identification techniques, such as measuring body proportions. However, fingerprints are not a foolproof way to find someone. Some diseases and medications can cause people to lose their fingerprints. A very small percentage of people are even born without them. This can make it difficult to get legal documents, enter different countries, and apply for certain jobs.

Answers to comprehension questions

1b 2b 3c