MCQ on Biometrical Genetics / Quantitative Genetics Part -9 For ARS NET / SRF Exams

 

1. Ability of a gene to express itself in the individuals carrying it in the appropriate genotype is known as
(i) Pleiotropy
(ii) Expressivity
(iii) Penetrance
(iv) Variable Expressivity

2. Ability of gene to express itself uniformly in all the individuals that carry it in the appropriate genotypes is known as
(i) Pleiotropy
(ii) Expressivity
(iii) Penetrance
(iv) Complete penetrance

3. Choose the correct statement
(i) Inheritance of quantitative characters are based on the multiple factor hypothesis, polygenic inheritance and continuous variation and estimation of environmental effects on quantitative characters
(ii) Inheritance of qualitative characters is based on dominance, segregation and independent assortment, penetrance and expressivity, pleiotropy, gene interaction, linkage, threshold character and modifying genes
(iii) Both (i) and (ii)
(iv) None of these

4. The frequency with which a gene produces a phenotypic or visible effects in the individuals which carry it is known as
(i) Pleiotropy
(ii) Expressivity
(iii) Penetrance
(iv) Variable Expressivity

5. The degree of phenotypic expressions of a penetrant gene is called as
(i) Pleiotropy
(ii) Expressivity
(iii) Penetrance
(iv) Complete penetrance

6. Choose the incorrect statement
(i) Expression of a gene in all the individuals which carry it is known as complete penetrance
(ii) When specific gene does not manifest its effect in all the individuals which carry this gene is known as incomplete penetrance
(iii) Differential or variable expression of a gene in the individuals that carry it is known as variable expressivity
(iv) Similar or uniform expression of a gene in all the individuals that carry such genes is called as complete penetrance

7. Characters whose development depends upon a specific environment are called as
(i) Quasi-quantitative characters
(ii) Threshold characters
(iii) Qualitative characters
(iv) None of these

8. Some genes that do not have any effect of their own on a given trait but they increase and decrease the expression of oligogenes governing the trait, such genes are known as
(i) Minor gene
(ii) Modifying genes
(iii) Major gene
(iv) Oligogenes

9. Choose the correct statement
(i) The term genetic background is often used as a synonym for modifying genes
(ii) The knowledge of threshold may be helpful in the identification of desirable genotypes from a population
(iii) Genes, which modify the effect of other genes but they do not seem to have any effect of their own on the concerned traits are called as modifying genes
(iv) All of these

10. Choose the correct statement
(i) Mutant gene in barley (Hordeum vulgare) produces albino seedlings at temperature below 8°C but at 19°C become normal green seedlings is an example of threshold characters
(ii) These genes show various relationships with each other in producing the concerned characters, these relationships are called as interaction
(iii) ‘S’ alleles in self-incompatibility and opaque2 (O2) gene of maize are example of modifying genes
(iv) All of these

11. The tendency of two more genes to remain together in the same chromosome during inheritance is known as
(i) Linkage
(ii) Penetrance
(iii) Pleiotropy
(iv) Modifying genes