Question

Tired of watering his garden, your instructor is attempting to grow desert plants. One such plant is Indian paintbrush. A yellow variant has shown up, and we would like to determine if this variant is a Mendelian trait. We have taken a pure breeding red plant and crossed it with a pure breeding yellow plant.

The resulting F1 plants were selfed and the F2 data is presented below: Red Flowers 299 Yellow Flowers 63 Perform a chi-square analysis on this data using the following hypothesis: The mode of inheritance for flower color in Indian paintbrush plants is simple Mendelian. What is the calculated chi-square value? Round to three decimal places.

we are supposed to find the ratio indicated by data but I'm confused about that portion, here is what I've done so far:

Phenotype	Observed #	Ratio Indicated by Data	Expected frequency	Expected #
Red	299	299/362 = 0.82596	?/4	(?/4)x362 =
Yellow	63	63/362 = 0.17403	?/4	(?/4)x362 =

Phenotype	Observed	Expected	O-E	(O-E)^2/E
Red	299
Yellow	63
Total	362	N/A	0

Answer 1

Answer:

Based on the F2 phenotypic ratio, red color may be considered as the dominant phenotype and yellow color may be considered as recessive phenotype. The expected F2 phenotypic ratio of monohybrid cross is 3/4 (dominant phenotype) : 1/4 (recessive phenotype).

Phenotype	Observed(O)	Expected (E)	O-E	(O-E)2	(O-E)2/E
Red	299	271.5	27.5	756.25	2.79
Yellow	63	90.5	-27.5	756.25	8.36
	362	362			11.142

Chi-square vale = 11.142