Question

please show steps for part A B C D and E thank you!

18. The color of pea plant flowers is a Mendelian trait. Tuq pea plants with purple flowers are crossed, you want to know what the pa ong the offspring, 80 have purple lowers, and 25 have white flowers. With a Goodness-of-fit chi-square test, setting the significance level at 0 05 (a), compare the observed numbers with a 3:1 ratio of purple to white and answer the following questions: a. What is the null and alternative hypotheses? 2pt Ho урс uhan you e ngahfe wn yeu cros You will 2 pea plants ith porple fowe HA you will be able to determinc the parental genotype whun yov cross 2 pea plamts b. How many degrees of freedom there are? 2pt. att,n-1 -) 2-1:1 (zpaplants) c. What is the obtained chi-square value? 4pt go Prp3-24010.66 White s15%1-2515-259- o 7 2U5 d. What is the obtained p-value? 2pt. Your p-valve at tu significance valve of os with a deqic of ficedom oF 2ill be 5.q9 According to your obtained results, write your final conclusion referring to the context of the problem based on an alpha of 0.05. 3pt. e. I:20 45.q you will rejet te nll hyothesis Snce your Pvae is greater

Answer 1

a)

Null hypothesis: The pea plant flower color is a simple Mendelian trait.

Alternative hypothesis: The pea plant flower color is not a simple Mendelian trait.

b)

df = n - 1. where n = number of expected phenotype.

So, df = 2 - 1 = 1

c)

Total number of observed flowers,

Purple = 80 , White = 25,

So, total number of flowers = 80 + 25 = 105.

The expected Mendelian ratio for monohybrid cross = 3 : 1.

So, the expected number of purple flowers = 105 * (3/4) = 78.75.

and the expected number of white flowers = 105 * (1/4) = 26.25.

Phenotype	Expected Frequency	Observed (O)	Expected (E)	O-E	(O-E)2 /E
Purple	3/4	80	78.75	1.25	0.02
White	1/4	25	26.25	-1.25	0.06
Total	1	105	105	0	0.08

d) So, the optained p value = 0.08

e) For df = 1 and significance level 0.05 the maximum p value we can count is 3.841.

Here, p value = 0.08.

So, we can not reject the null hypothesis. { We can only reject the null hypothesis if the p value comes beyond 3.841}

So, the flower color trait is a Mendelian trait.