Question

Okay, so i got a question about phenotype, and geneotype, and i dont know how to do it. The question is: Some trolls have one eye (EE, Ee) while others have two (ee). Two heterozygous one eyed trolls are crossed. What is the expected genotype ratio of the two eyed offspring?

Answer 1

Answer:

25% is the expected genotype ratio of the two-eyed offspring.

Explanation:

• First, we analyze the information that we have:
• EE or Ee are trolls with one eye.
• ee are trolls with two eyes.
• E is dominant and is the gene responsible for one eye.
• e is recessive and is the gen responsible for two eyes.
• If two heterozygous trolls are crossed that means that both trolls are Ee, they have different copies of the same gene.
• After looking at the information, we draw a Punnett Square, and we can see that there is a 25% that their offspring is a two-eyed troll (ee).  

║ E ║ e ║

E║ EE ║ Ee ║

e ║ eE ║ ee ║

Answer 2

Answer:

= 25 %

Explanation:

Given that :

the genotype attributed to  trolls having one eye  = (EE, Ee);  that is homzygous dominant or heterozygote dominant for eye number

Likewise those that posses two eyes have (ee) ; that is homzygous recessive

Now; two heterozygous one eyed trolls are crossed ; we have :

Ee  × Ee

The punnet square for this cross looks like what we have below:

               E                e

E              EE              Ee

e              Ee               ee

From the above cross; we have:

1   EE    ---- (homozygous dominant ) indicating troll having one eye

2  Ee    ---- ( heterozygote dominant ) indicating troll having one eye

1  ee    ----- ( homozygous recessive ) indicating troll having two eyes

The genotypic ratio is 1:2:1

Thus; the expected genotype ratio of the two eyed offspring = $\frac{1}{4}*100$

= 25 %