Mastery Check #3 - Mutations (Note: Punnett squares are also on this mastery check. See the other link under genetics to learn about Punnett squares)
What is a mutation? A mutation is a change in the genetic code of an organism. These changes can cause organisms to have traits that are helpful, harmful, or neutral. Mutations are random and organisms cannot choose to have them in order to help them survive.
- Mutations that are helpful will help the organism survive and the helpful trait will be passed to their offspring. This causes helpful mutations to become more common in a population.
- Mutations that are harmful will make it hard for the organism to survive and will most likely not be passed to their offspring. This causes harmful mutation to be less common in a population.
Mutation = Albino penguins
Mutation = The ability to digest lactose
In most school lunchrooms, a common drink to go with lunch is milk, but it wasn’t until a few thousand years ago that humans could even digest milk past childhood. Most babies can digest milk without getting an upset stomach thanks to an enzyme called lactase. Up until several thousand years ago, that enzyme turned off once a person grew into adulthood — meaning most adults were lactose intolerant. Lactose is the part of milk that makes it difficult for people to digest milk. Now, thirty-five percent of people can digest milk without any problems.
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The situation on the left is an example of a mutation that is helpful. This allows people to have another food source when they are adult.
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Mutation = hemophelia
The situation on the right is an example of a mutation that is harmful. This can be a dangerous disease, but most people with it can lead a normal life.
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Bumps and scrapes are a normal part of childhood. For most kids, a tumble off a bike or a stray kick in a soccer game means a temporary bruise or a cut that heals with a scab. However, for kids with hemophilia, these everyday mishaps are cause for concern.Hemophilia is a disease that prevents blood from clotting properly. Clotting helps stop bleeding after a cut or injury. If clotting doesn't happen, a wound can bleed too much.
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