3.8 Dominant or Recessive?
A. Who gets what traits?
When you inherit traits, they are passed down from your parents. You get one gene from each parent.
If your mom has brown hair and your dad has brown hair, you are probably going to have brown hair. But what if your mom has brown hair and your dad has blond hair. What color hair will you have? This depends on which trait is dominant or stronger and which is weaker or recessive.
Let’s look back at some of the traits we’ve seen before. Based on the chart you made, which trait do you think was dominant and which was recessive? Why?
Which is dominant? Which is recessive?
Which is dominant? Which is recessive?
B. Dominant or Recessive
Our DNA is inherited from our parents. Humans have 46 chromosomes. 23 come from the mother and 23 come from the father. Each chromosome has a full copy of traits. Sometimes we get one trait from one parent and a different trait from another parent. If there are mutations on those chromosomes, we can inherit those mutations too.
If we want to change DNA to make super heroes we have to understand how we get our DNA in the first place, where it comes from, and how the genes know what to do.
You read in the article that some genes are dominant, they take charge, and some are recessive, they do what dominant genes tell them. If both parents are dominant, we inherit the dominant trait. If both parents are recessive, we inherit the recessive trait. But what happens when to code in our DNA conflicts? What if one parent is dominant and the other is recessive? That could impact a parent’s ability to pass down a super trait
Let’s find out how dominant and recessive genes work using a good old fashioned coin flip. Before you start, which do you think will happen more often dominant or recessive? Why?
Directions: In your Mission Log complete the Patterns of Inheritance coin flip activity to find out which are most common, dominant or recessive traits.
When you are done, check your answers to the reflection questions below.
C. Battle of the Traits
Directions: Read the “Battle of the Traits.” As you read, think about:
- What is the meaning of these four words: dominant, recessive, heterozyygos, homozygous?
- How does your body decide which traits you get when you get different traits from each parent?
D. Super Sight Punnett Practice
A Punnett square shows the different possible ways an offspring could inherit traits from parents. Imagine a set of parents with traits for super sight. The normal sight trait is “T” the super sight trait is “t”.
Directions: Complete the punnet squares below and decide which pair of parents COULD have an offspring with super sight. Parents 1+2 or parents 3+4:
- Dragging the alleles to the right places on the square.
- Decide which squares are heterozygous and which are homozygous.
E. Punnett Practice Round 2
Now let’s see how punnett squares work in the real world with real-world traits.
Directions: Complete the Punnett Square practice in your Mission Log.
When you are done, check your answers to the reflection questions below.
You must be logged in to post a comment.