ASRB NET - Agricultural Statistics (and Computer Application / Bioinformatics) · India · Agricultural Scientists Recruitment Board (ICAR)
Original practice questions written to the published syllabus · not past papersThe analyses a breeding programme runs every season: path analysis, D-squared divergence, diallel and line x tester analysis for combining ability, generation-mean analysis, North Carolina designs, heterosis, prediction of response to selection and the construction of selection indices.
In the exams: AICE-JRF Ag Stat Unit 3 'path coefficient analysis, heterosis, GCA and SCA, diallel, line x tester, response to selection, selection index' (heavy); AICE-JRF Genetics & Plant Breeding (heavy); ASRB NET Ag Stat (heavy)
ASRB NET / ARS Agricultural Statistics and Plant Breeding
Applied biometrical analysis and interpretation for breeding decisions.
How our questions for ASRB NET spread across the units of Biometrical Techniques in Plant & Animal Breeding. Difficulty: 13 easy, 52 medium, 23 hard.
| Diallel crosses: Griffing's methods and Hayman's approach | 11 | |
| Genotypic and phenotypic correlations and path coefficient analysis | 10 | |
| Generation mean analysis and scaling tests | 9 | |
| Heterosis and inbreeding depression | 8 | |
| Response to selection: individual, family and combined | 8 | |
| Construction of selection indices (Smith-Hazel) | 8 | |
| Sire evaluation and breeding-value estimation in animals | 8 | |
| Genetic divergence: Mahalanobis D-squared and clustering | 7 | |
| Line x tester analysis | 7 | |
| North Carolina designs and triple test cross | 7 | |
| Stability parameters for breeding lines | 5 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
With sigma^2 g = 16 and sigma^2 e = 9, what is broad-sense heritability?
C. 0.64
h^2 = 16/(16 + 9) = 0.64; 0.80 is sqrt(0.64).
Further reading: Singh and Chaudhary, Biometrical Methods in Quantitative Genetic Analysis; Falconer and Mackay, Introduction to Quantitative Genetics
With r1y = 0.6, r2y = 0.5 and r12 = 0.3, what is the direct path coefficient of trait 1 on yield?
C. 0.495
Solve P1 + 0.3P2 = 0.6, 0.3P1 + P2 = 0.5: P1 = 0.45/0.91 = 0.495, P2 = 0.352.
Further reading: Singh and Chaudhary, Biometrical Methods in Quantitative Genetic Analysis; Falconer and Mackay, Introduction to Quantitative Genetics
In Griffing's method 2 with 7 parents, how many df does SCA have?
A. 21
p(p - 1)/2 = 21; entries 28, GCA 6.
Further reading: Singh and Chaudhary, Biometrical Methods in Quantitative Genetic Analysis; Falconer and Mackay, Introduction to Quantitative Genetics
What value of H2/4H1 indicates equal frequencies of genes with positive and negative effects?
D. 0.25
H2/4H1 = uv, maximal at 0.25 when u = v = 0.5.
Further reading: Singh and Chaudhary, Biometrical Methods in Quantitative Genetic Analysis; Falconer and Mackay, Introduction to Quantitative Genetics
Where do parents with more dominant genes lie on the Wr-Vr regression line?
C. Near the origin
Parents with most dominant genes have the smallest Wr and Vr.
Further reading: Singh and Chaudhary, Biometrical Methods in Quantitative Genetic Analysis; Falconer and Mackay, Introduction to Quantitative Genetics
With 10 lines and 3 testers, how many crosses are there?
C. 30
Each of the 10 lines is crossed with each of the 3 testers: l x t = 30.
Further reading: Singh and Chaudhary, Biometrical Methods in Quantitative Genetic Analysis; Falconer and Mackay, Introduction to Quantitative Genetics
Which design suits a cross between two inbreds when testing epistasis directly?
B. Triple test cross
TTC crosses F2 individuals to P1, P2 and F1.
Further reading: Singh and Chaudhary, Biometrical Methods in Quantitative Genetic Analysis; Falconer and Mackay, Introduction to Quantitative Genetics
With h^2 = 0.25, what is k = (4 - h^2)/h^2 in the sire index?
D. 15
k = (4 - 0.25)/0.25 = 3.75/0.25 = 15.
Further reading: Singh and Chaudhary, Biometrical Methods in Quantitative Genetic Analysis; Falconer and Mackay, Introduction to Quantitative Genetics
With h^2 = 0.25, what is the accuracy with 100 daughters?
C. 0.93
sqrt(100/(100 + 15)) = 0.93.
Further reading: Singh and Chaudhary, Biometrical Methods in Quantitative Genetic Analysis; Falconer and Mackay, Introduction to Quantitative Genetics
A breeding line has high mean, b near 1 and small deviations. It is suited to:
A. Wide adaptation
Eberhart-Russell criteria for broad adaptation.
Further reading: Singh and Chaudhary, Biometrical Methods in Quantitative Genetic Analysis; Falconer and Mackay, Introduction to Quantitative Genetics
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