Question

The allele for having freckles (F) is dominant over the allele for not having freckles (f). Some characteristics in people are inherited as simple dominant and recessive traits. One example is freckles. Freckles is a dominant trait, and the lack of freckles is a recessive trait. In this example, a person with freckles is represented as either FF or Ff, and a person with no freckles is represented as ff. Total score: ____ of 20 points (Score for Question 1: ___ of 2 points) 1. Imagine a mother and a father who both have freckles and are heterozygous for the trait, or Ff. They are the P generation, or parent generation. Create a Punnett square to show their offspring, the F1 generation. Answer: Type your answer here. Part 1 Punnett Square (Score for Question 2: ___ of 2 points) 2. Calculate the ratios of the genotypes and phenotypes of the offspring in the F1 generation. Answer: Type your answer here. Genotypes: Phenotypes: Part 2: Dihybrid Cross—Predicting Flower Color and Se

Answer 1

Question no 1:

As mentioned in the question that parents are heterozygous for freckles (Ff).

Please see the punnet square in attached picture.

Question no 2:

As we can see in figure offspring will be as:

P1:                      Ff X Ff

F1:                  FF:  Ff : Ff : ff

Phenotypic ratio:          3: 1

Genotypic ratio:           1: 2: 1

This is because freckles is a dominant trait and even one allele of dominant treat is enough to cause freckles to the offspring. However genotypically there is a difference between FF and Ff because the Ff will have lower chances to inherit the trait to offspring and FF will have more chances to transfer the trait to next offspring.

Hope it helps!

Answer 2

Answer:

First thing you need to do is get the alleles of the mother and father. They are heterozygous dominant for freckles, their genotypes are Ff. Your Punnett would look like this:

P generation cross: Ff x Ff

      F       f

F   FF     Ff

f    Ff      ff

Looking at the Punnett, just list all the possible genotype combinations, then count how many you see in the Punnett. But when you tlak about phenotype, you will be looking at what was expressed. Since Freckles are dominant, when there is at least 1 dominant allele in the combination, the dominant trait will be expressed.

Genotype       Number         Phenotype

    FF                    1                  Freckles

    Ff                    2                  Freckles

    ff                     1                  No Freckles

You can see that FF and Ff will both express freckles, so you add up their ratio.

Based on this:

genotype ratio would be 1 FF: 2 Ff: 1 ff or 1:2:1

phenotype ration would be: 3 Freckles: 1 No freckles or 3:1