Question

Can YOU curl your tongue up on the sides? We are pretending that tongue-curling in humans is a dominant genetic trait. Suppose a man who is Tt for tongue-curling marries a woman who is also Tt for this trait. What are the possible genotypes and phenotypes of their children, and the percent chance for each? Genotype Phenotype (curl or no curl) Percent Chance (number only) TT Tt tt Word Bank: 255075 curl no curl25curl 0100 Blank 1: Blank 2: Blank 3: Blank 4: Blank 5: Blank 6:

Answer 1

To determine the possible genotypes and phenotypes of the children of two parents who are both Tt for tongue-curling, we can set up a Punnett square.

The parents' genotypes are:
- Man: Tt
- Woman: Tt

The possible gametes from each parent are T and t. When we set up the Punnett square:

```
T t
-----------------
T | TT | Tt |
-----------------
t | Tt | tt |
-----------------
```

From this Punnett square, we see the following potential genotypes for their children:
- **TT** (homozygous dominant) - Curling Trait
- **Tt** (heterozygous) - Curling Trait
- **tt** (homozygous recessive) - No Curling Trait

Now, let's list the phenotypes:
- **Curling Trait:** (TT and Tt)
- **No Curling Trait:** (tt)

Now, calculating the percentages:
1. Genotype TT: 1 out of 4 possibilities → **25%**
2. Genotype Tt: 2 out of 4 possibilities → **50%**
3. Genotype tt: 1 out of 4 possibilities → **25%**

The combined percentages for the phenotypes are:
- Curling Trait: 3 out of 4 possibilities (TT + Tt) → **75%**
- No Curling Trait: 1 out of 4 possibilities (tt) → **25%**

So filling in your blanks, we have:

Blank 1: 25
Blank 2: 75
Blank 3: TT
Blank 4: Tt
Blank 5: tt
Blank 6: 25

Final Answers:
- Blank 1: 25 (percentage of TT)
- Blank 2: 75 (percentage of curling phenotypes)
- Blank 3: TT (genotype)
- Blank 4: Tt (genotype)
- Blank 5: tt (genotype)
- Blank 6: 25 (percentage of no curl phenotype)