In a certain species of chile pepper, there are three different fruit pod colors
ID: 149211 • Letter: I
Question
In a certain species of chile pepper, there are three different fruit pod colors that can be produced: yellow, orange and red. A plant with red-colored fruit is crossed with a plant with yellow-colored fruit. All of the progeny from this cross produce red-colored fruit. Numerous plants with red-colored fruit from this generation are crossed with one another. Progeny from these crosses are planted, flowered, and allowed to produce fruit. When plants produce fruit, there are 133 plants that produce red-colored fruit, 13 plants than produce yellow-colored fruit and 29 plants that produce orange-colored fruit. Hypothesize on how this trait for fruit color is being inherited in this species of chile pepper. Please show your evidence and/or calculations that support your hypothesis. Please provide the suspected genotypes of the different plants in this problem
Explanation / Answer
Let us assume that the plants that produced red colored flowers were homozygous for the red color which is dominant (as we saw from the next generation). RR.
Let us assume that the plants that produced yellow colored flowers were homozygous for yellow color which is the recessive trait. rr.
A cross between RR and rr will give all progeny as Rr. These have a red color. This proves that red is dominant over yellow.
Now, a cross between Rr and Rr will give the following type of progeny:
RR (Red)
Rr (orange)
rr (yellow)
This is an example of inheritance by multiple alleles.
Or, the pod color depends on more than one gene. There may be a trait at another locus which determines the expression of this trait.
Otherwise, the inheritance could be autosomal recessive.
The possible genotypes are RRo and rro .
The progeny are Rro and Ro r.
On being crossed, these could yield Ro ro . This would give an orange color.
This would give a phenotypic ratio of Red: Orange: yellow as 2:1:1
R ro Ro RoR Ro ro r Rr rro