Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Assume that a cross is made between a heterozygous tall pea plant and a homozygo

ID: 13957 • Letter: A

Question

Assume that a cross is made between a heterozygous tall pea plant and a homozygous short pea plant. Fifty offspring are produced in the following frequency: 30= tall and 20= short.
a) what frequency of tall and short plant is expected
b) If one wanted to test the goodness of fit between the observed and expected values, provide a statement of the null hypothesis.
c) compare a chi-square value associated with this appropriate test of significance.
d) How many degrees of freedom are associated with this test of significance?

Explanation / Answer

TALL allele-------T,

SHORT allele------t,

homozygous short pea plant.--------tt

heterozygous tall pea plant----Tt

a heterozygous tall pea plant and a homozygous short pea plant

tall pea plant----Tt       x short pea plant.--------tt

T

t

t

Tt

Tt

t

Tt

Tt

TALL :SHORT; 3:1= 75% :25:%

ACCORDING HARDY WEINBERG LAW

P^2+2PQ+ q^2=1

q^2=recessive homozygotes

q^2=20/50= short. q =0.63

P+q=1

P=1- q =1-0.63=0.37

GENOTYPE

OBSEERVED

EXPECTED

O-E

(O-E)^2

(O-E)^2/E

P^2=TT

30

29.8

.2

0

0.0013

2PQ=2Tt

q^2=tt

20

19.84

0.06

1.81

P^2=TT=0.37 x0.37x50=6.8

2pq=2Tt=2x 0.37 x0.63x50=23

q^2=19.84


a) what frequency of tall and short plant is expected

GENOTYPE

OBSEERVED

EXPECTED

P^2=TT

30

29.8

2PQ=2Tt

q^2=tt

20

19.84


b) If one wanted to test the goodness of fit between the observed and expected values, provide a statement of the null hypothesis.

There is no difference between obserevd and expected frequencies
c) compare a chi-square value associated with this appropriate test of significance.

Calculatec value is less than table value ,null hypotheiss is acepeted
d) How many degrees of freedom are associated with this test of significance?

5% ------ test of significance

degrees of freedom= (n-1) x(c-1)=1x1=1

T

t

t

Tt

Tt

t

Tt

Tt

Hire Me For All Your Tutoring Needs
Integrity-first tutoring: clear explanations, guidance, and feedback.
Drop an Email at
drjack9650@gmail.com
Chat Now And Get Quote