Sample Group Work

Alien Genetics

Directions: Using the traits listed below, build a Punnet square for the following crosses. Use this activity to understand how each parent contributes one allele to the offspring. Build the Punnet squares using the grid marked on the poster paper

Traits:
  • One Eye (E) vs. Two Eyes (e)
  • Three Fingers (F) vs. Two Fingers (f)
  • Green Skin (G) vs. Blue skin (g)
  • Two Antennae (A) vs. One Antennae (a)
  • Four Toes (T) vs. Six Toes (t)
Questions:
1. Homozygous dominant male for eyes mates with a heterozygous female. What are the genotypes of her offspring? Build the living Punnet square and when you're ready, call for the teacher.
  

 
2. Two heterozygous for fingers Martians marry and have four kids. How many of their kids will have three fingers? How many will have two? Build the living Punnet square and when you're ready, call for the teacher.

   

3. A homozygous recessive for skin color female Martian has children with a heterozygous male. What are the genotype possibilities for her four children? Build the living Punnet square and when you're ready, call for the teacher.

    
4. A homozygous dominant for antennae mates with a homozygous recessive female. What phenotypes are shown in their four children?

     


5. A male Martian that is heterozygous for toes marries a female martin that is homozygous recessive. What are the chances (in %) that their children will be heterozygous?