The document describes how a Punnett square is used to determine the possible genotypes and phenotypes of offspring from a cross between pea plants. It notes that there are two alleles that determine height in pea plants: the Tall (T) allele which is dominant, and the Short (t) allele which is recessive. The Punnett square shows that if one parent is homozygous tall (TT) and the other is heterozygous (Tt), the offspring will all be tall (TT or Tt genotypes).
1. Punnett Square
T t
TT = Tall
Tt = Tall
T TT Tt
Tt = Tall
tt = Short
t Tt tt
2. Pea Plants
The gene for height has two alleles:
- 1st allele = Tall
- 2nd allele = Short
-Tall
- Dominant Tall allele
-T
- Short
- Recessive Short allele
-t
3. * Tall (T) is dominant and Short (t) is recessive.
4. * Tall (T) is dominant and Short (t) is recessive.
5. * Tall (T) is dominant and Short (t) is recessive.
6. = Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
7. = Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
8. = Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
9. = Tall
=Tall
Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
10. = Tall
=Tall
Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
11. = Tall
=Tall
Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
12. = Tall
=Tall
Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
13. = Tall
=Tall
Tall Tall
=Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
14. = Tall
=Tall
Tall Tall
=Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
15. = Tall
=Tall
Tall Tall
=Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
16. = Tall
=Tall
Tall Tall
=Tall
Tall
* Tall (T) is dominant and Short (t) is recessive.
17. = Tall
=Tall
Tall Tall
=Tall
=Short Tall Short
* Tall (T) is dominant and Short (t) is recessive.
18. = Tall
T t
=Tall
T TT Tall Tt Tall
=Tall
=Short t Tt Tall tt Short
* Tall (T) is dominant and Short (t) is recessive.