Animal Breeding and Genetics (ABG) MCQS Set 3
51. Gene embodies a coded message, in the form a sequence of Chemical Units called,
a) Nucleoside
b) DNA
c) Nucleotide
d) Ribose sugar
Correct Answer: c) Nucleotide
52. Sometime DNA undergoes a sequence change, termed _________ that alters both genotype and phenotype.
a) Genetic shift
b) Genetic Drift
c) Mutation
d) Replication
Correct Answer: c) Mutation
Explanation: A mutation is a permanent alteration in the DNA sequence. This change creates a new genotype which can result in a different physical expression or phenotype.
53. Mutation is ultimate source of ____________
a) Gene frequency Change
b) Replication
c) Phenotypic Variation
d) Genetic Variation
Correct Answer: d) Genetic Variation
Explanation: Mutation is the primary process that creates new alleles, making it the ultimate source of all genetic variation upon which selection and evolution act.
54. Mutation is sometime give an advantage to an organism by,
a) More lifespan
b) Resistant to Disease
c) More off-spring
d) More production
Correct Answer: b) Resistant to Disease
Explanation: While many mutations are harmful or neutral, some can provide a survival advantage, such as resistance to a specific disease, allowing the organism to thrive in environments where others perish.
55. A revolution occurred in molecular genetics by invention of,
a) Gene isolation
b) Recombinant DNA Technology
c) Artificial Insemination
d) DNA polymerase
Correct Answer: b) Recombinant DNA Technology
Explanation: Recombinant DNA Technology allowed scientists to combine DNA from different sources, leading to a revolution in biotechnology, gene therapy, and the production of genetically modified organisms.
56. _________ analysis the pattern of Distribution of genes in Population of Organism.
a) Transmission genetics
b) Molecular Genetics
c) Breeding
d) Population Genetics
Correct Answer: d) Population Genetics
Explanation: Population Genetics studies how the distribution and frequency of alleles change within a population over time due to selection, drift, and mutation.*
57. Population genetics measures _______
a) Genes
b) Heredity
c) Allele frequency
d) Gene frequency
Correct Answer: d) Gene frequency
Explanation: A core measurement in population genetics is gene frequency (or allele frequency), which tracks how often a particular version of a gene appears in a population.
58. Quantitative Genetics is simple extension of,
a) Mendalian Genetics
b) Transmission Genetics
c) Molecular genetics
d) Population Genetics
Correct Answer: a) Mendalian Genetics
Explanation: Quantitative Genetics applies the principles of Mendelian Genetics to traits controlled by many genes (polygenic), where individual gene effects are small and continuous variation is observed.
59. The phenotypic value is effect of ,
a) Phenotype alone
b) Genotype alone
c) Environment alone
d) B and C
Correct Answer: d) B and C
Explanation: The Phenotype (P) is the result of the interaction between the individual’s Genotype (G) and the Environment (E) ($P = G + E$).
60. The genotype value is effect of
a) Nuclear genes
b) Mitochondrial genes
c) Genes interaction
d) All of the above
Correct Answer: d) All of the above
Explanation: The total genotypic value includes the additive effects of nuclear genes, the influence of mitochondrial DNA, and the non-additive effects of gene interactions (epistasis).
61. The heritability of a trait is proportion of
a) VP (Phenotypic Variance)
b) VE (Environmental Variance)
c) VD (Dominance Variance)
d) All above
Correct Answer: a) VP
Explanation: Heritability ($h^2$) is defined as the proportion of the total phenotypic variance (VP) that is attributable to genetic variance.*
62. The best individual from each family is used for breeding in?
a) Between family selection
b) Within family selection
c) Mass selection
d) Progeny Selection
Correct Answer: b) Within family selection
Explanation: In within-family selection, the best performing individual is chosen from each family group, which helps maintain genetic diversity and reduces inbreeding compared to mass selection.
63. Broad sense heritability is denoted by
a) H2
b) h2
c) G
d) E
Correct Answer: a) H2
Explanation: Broad-sense heritability is denoted by $H^2$ and represents the proportion of phenotypic variance due to all genetic effects. Narrow-sense heritability is denoted by $h^2$.
64. The main parts of the cell includes ______ and cytoplasm
a) Mitochondria
b) Gene
c) Nucleus
d) Chromosome
Correct Answer: c) Nucleus
Explanation: In basic biology, an animal cell is primarily divided into the Nucleus (the control center) and the Cytoplasm (where most metabolic activities occur).
65. A _______ is the simply functional segment of DNA thread,
a) Peptide chain
b) Chromosome
c) Gene
d) Chromatid
Correct Answer: c) Gene
Explanation: A gene is the specific functional segment of the long DNA molecule that contains the code for a protein or a functional RNA.
66. Method use for conservation of breed is,
a) Cross breeding
b) Line breeding
c) Inbreeding
d) Selection
Correct Answer: c) Inbreeding
Explanation: While selection is used to improve, inbreeding (specifically purebreeding) is the method used to conserve the specific genetic characteristics and purity of a particular breed.
67. Reduce fertility, slow growth rate, greater susceptibility to disease and high mortality rate in ________
a) Cross breeding
b) Out breeding
c) Inbreeding
d) Progeny testing
Correct Answer: c) Inbreeding
Explanation: These are the classic symptoms of inbreeding depression, which occurs when harmful recessive genes become homozygous in a population due to mating related individuals.
68. Female sire by a bull of particular breed are mated to bull of another breed, this is called?
a) Two breed rotational cross
b) Two breed cross
c) Cross breeding
d) Three breed rotational cross
Correct Answer: a) Two breed rotational cross
Explanation: In a two-breed rotational cross, female offspring of Breed A are mated to Breed B, and their female offspring are then mated back to Breed A.
69. Milk is a _____ trait
a) Qualitative trait
b) Quantitative trait
c) Complementary trait
d) Rotational trait
Correct Answer: b) Quantitative trait
Explanation: Milk production is a quantitative trait because it is controlled by many genes and environmental factors, showing continuous variation across a range.
70. Homozygosity is commonly seen in?
a) Inbreeding
b) Line breeding
c) Out breeding
d) Cross breeding
Correct Answer: a) Inbreeding
Explanation: Inbreeding increases the probability that an individual will receive identical alleles from both parents, thereby increasing homozygosity.*
71. Sheep have ____ Pair of Chromosome
a) 62
b) 32
c) 31
d) 27
Correct Answer: d) 27
Explanation: Sheep have a diploid number ($2n$) of 54, which means they have 27 pairs of chromosomes. Note: The option ‘d’ provided in your prompt (23) is incorrect for sheep; the correct pair number is 27.
72. Buffalo have _____ number of Chromosome?
a) 24
b) 46
c) 48
d) 23
Correct Answer: c) 48
Explanation: Swamp buffaloes have 48 chromosomes, while River buffaloes have 50. In the context of the options provided, 48 is the most accurate for the species.
73. The advantage of cross breeding at F1 stage is?
a) Breed complementarity
b) Heterosis
c) Good health of F1
d) Disease resistance in F1
Correct Answer: b) Heterosis
Explanation: The F1 generation of a cross between two unrelated breeds exhibits maximum heterosis (hybrid vigor), often performing better than the average of the two parent breeds.
74. Crossbreeding have advantage
a) Breed complementarity
b) Hybrid Vigor
c) a and b
d) none of above
Correct Answer: c) a and b
Explanation: Crossbreeding offers two major genetic advantages: Heterosis (Hybrid Vigor) and Breed Complementarity (combining the strong points of different breeds).
75. Heterosis is more expressive in F1 when?
a) Breeds are more genetically similar
b) Breeds are more genetically dissimilar
c) Breeds of same country
d) Breeds of different country
Correct Answer: b) Breeds are more genetically dissimilar
Explanation: Heterosis is typically maximized when the parent breeds are genetically distant (dissimilar), as this leads to the greatest increase in heterozygosity in the offspring.*