A true-breeding purple-leafed plant isolated from one side of El ...

Question

A true-breeding purple-leafed plant isolated from one side of El Yunque, the rain forest in Puerto Rico, was crossed to a true-breeding white variety found on the other side. The F₁ offspring were all purple. A large number of F₁ x F₁ crosses produced the following results:

purple: 4219 white: 5781 (Total = 10,000)

Propose an explanation for the inheritance of leaf color. As a geneticist, how might you go about testing your hypothesis? Describe the genetic experiments that you would conduct.

Accepted Answer

Hi everyone. Let's look at our next problem. It says when a homocide dominant pea plant with blue flower, Big B. Big B. Is cross spread with the homos, I guess recessive pea plant with white flour. Little W little W. What is the expected ratio of the genotype Big B. Big B. And Big B. Little W. And the F. Two progeny. So a lot of stuff thrown at us here, let's think through what it's asking us about. So this is saying we started with this homicide is dominant plant Big B, Big B. And we cross spread it with our homes I guess recessive pea plant little W. Little W. Well that cross is going to result in an f. one generation that are all Hetero Zegas, Bigby little W. All the offspring will end up that way. But now it's asking us for genotype ratios in the F two generation. So the F two generation would be the result of self pollinating, be big be little W. Across a big B. Little W. A mono hybrid cross. And it's asking us what's the expected rate of ratio of the genotype Big B. Big B to big B. Little W. And there was a ratio of the homos, I guess dominant to the heterocyclic. Well, we might be able to pull off the top of our head if we're thinking of a mono hybrid cross, we know that the ratio of homesickness, dominant headers I guess will be 1-2. So that's our answer choice B. As our correct answer here. But we can look at the planet square if we just want to confirm that, and we'll just pop up that simple four square pendant square. And we see we have our hetero zegas cross here. Big B. Little W. Big B, little W. Here's our homicide is dominant. Then we see two squares for hetero cigarettes and one square for homesickness recessive. So indeed, we see this ratio of 1 to 2 shown in our punnett square. So again, our answer, the expected ratio of the genotype, Big B. Big B. And big D. Little W. In the F. Two Progeny is choice B. One to to see you in the next video.

Key Concepts

Mendelian Inheritance

Phenotypic Ratio

Genetic Testing and Experimental Design

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