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

A study on mixed species cloning was conducted to test if a non-human donor spec

ID: 3217636 • Letter: A

Question

A study on mixed species cloning was conducted to test if a non-human donor species could provide an egg for insertion of human dna for the clonal production of human stem cells. So an experiment was conducted in which unfertilized eggs were obtained from two species (pigs and sheep; 3 individuals of each species) and their nucleus was replaced with the nucleus from one of 12 human donors chosen at random. Four eggs from each individual pig or sheep were harvested and their nuclei removed and replaced with human donor nuclei; two from one human and two from another. After the eggs developed, an embryonic stem cell was obtained from each embryo and the number of mutations in a specific gene sequence was determined. Is there a significant difference in the number of mutations between stem cells derived from pigs vs. sheep? How much variation in the number of mutations can be attributed to differences among humans? [YOU MAY ASSUME THAT ALL ASSUMPTIONS ARE MET FOR THIS QUESTION] Please use spss if possible. Please state the test you used and please include graphs

Explanation / Answer

Answer:

A study on mixed species cloning was conducted to test if a non-human donor species could provide an

egg for insertion of human dna for the clonal production of human stem cells. So an experiment was

conducted in which unfertilized eggs were obtained from two species (pigs and sheep; 3 individuals of each

species) and their nucleus was replaced with the nucleus from one of 12 human donors chosen at random.

Four eggs from each individual pig or sheep were harvested and their nuclei removed and replaced with

human donor nuclei; two from one human and two from another. After the eggs developed, an embryonic

stem cell was obtained from each embryo and the number of mutations in a specific gene sequence was

determined.

Is there a significant difference in the number of mutations between stem cells derived from pigs

vs. sheep?

Group Statistics

Species

N

Mean

Std. Deviation

Std. Error Mean

mutations

pig

12

3.50

1.977

.571

sheep

12

9.83

3.486

1.006

Independent Samples Test

Levene's Test for Equality of Variances

t-test for Equality of Means

F

Sig.

t

df

Sig. (2-tailed)

Mean Difference

Std. Error Difference

95% Confidence Interval of the Difference

Lower

Upper

mutations

Equal variances assumed

5.815

.025

-5.474

22

.000

-6.333

1.157

-8.733

-3.934

Equal variances not assumed

-5.474

17.414

.000

-6.333

1.157

-8.770

-3.897

Calculated t=-5.474, P=0.000 which is < 0.05 level of significance.

There is a significant difference in the number of mutations between stem cells derived from pigs

vs. sheep.

How much variation in the number of mutations can be attributed to differences among humans?

[YOU MAY ASSUME THAT ALL ASSUMPTIONS ARE MET FOR THIS QUESTION]

Model Summary

Model

R

R Square

Adjusted R Square

Std. Error of the Estimate

1

.761a

.580

.560

2.824

a. Predictors: (Constant), humans

ANOVAa

Model

Sum of Squares

df

Mean Square

F

Sig.

1

Regression

241.850

1

241.850

30.320

.000b

Residual

175.484

22

7.977

Total

417.333

23

a. Dependent Variable: mutations

b. Predictors: (Constant), humans

Coefficientsa

Model

Unstandardized Coefficients

Standardized Coefficients

t

Sig.

95.0% Confidence Interval for B

B

Std. Error

Beta

Lower Bound

Upper Bound

1

(Constant)

.689

1.229

.561

.581

-1.860

3.238

humans

.920

.167

.761

5.506

.000

.573

1.266

a. Dependent Variable: mutations

R square =0.580

58.0% variation in the number of mutations can be attributed to differences among humans.

Group Statistics

Species

N

Mean

Std. Deviation

Std. Error Mean

mutations

pig

12

3.50

1.977

.571

sheep

12

9.83

3.486

1.006