Biology
Genetics and Plant Breeding
1,240 Questions
Genetics and Plant Breeding explores the principles of heredity, chromosomal inheritance, and hybridization techniques. It includes key concepts like Mendelian genetics, gene linkage, and polygenic inheritance. This topic is essential for students tackling advanced biology or botany sections in competitive examinations.
Mendelian InheritanceChromosome TheoryGene LinkagePolygenic InheritancePlant HybridizationPopulation Genetics Equilibrium
Genetics and Plant Breeding Questions
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ABO blood type evidence
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HLA type evidence
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DNA sequence evidence
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All are equally likely to be accepted
A
Correct answer
Explanation
Because of the Bombay Phenotype and other possible exceptions, the ABO blood type system is not conclusive in determining whether or not someone could be a parent of a particular child.
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O is dominant over A.
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B is dominant over A.
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O is recessive to all other alleles.
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A is dominant over B.
C
Correct answer
Explanation
The rules of dominance for the ABO system are that A and B are both dominant over O (i.e. O is recessive) and A and B are co-dominant.
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They may be homozygous dominant (DD) or heterozygous (Dd) for this trait.
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They all are strictly homozygous dominant (DD) for the trait.
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They all are strictly homozygous recessive (dd).
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They may be homozygous recessive (dd) or heterozygous (Dd) for the trait.
A
Correct answer
Explanation
The Rh blood factor is a dominant trait. Therefore, both DD and Dd people have the Rh antigen on the surface of their red cells which makes them Rh positive.
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Homozygous-dominant
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Homozygous recessive
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Heterozygous
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Carrier
B
Correct answer
Explanation
Homozygous recessive is defined as a diploid carrying two copies of the recessive allele of the examined gene. Since the ability to taste PTC is a dominant allele, therefore this genotype will be least expressed by this person.
B
Correct answer
Explanation
Out of total progenies, 25 % will have O blood group. When both parents have blood types BO, then it is possible that they can produce a child of O blood group.
D
Correct answer
Explanation
Since white flowers are the recessive traits in Pisum sativum, the genotype of the parents would be pp x pp, where P= gene for a purple flower and p= gene for a white flower. Because it is a recessive trait, both white flowered parents must be homozygous recessive. Therefore, all of their offsprings will also have white flowers, because that is the only gene available.
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Phenotype
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Genotype
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allele
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Gene pool
A
Correct answer
Explanation
The output of the genes is the phenotypic character which physically observed. Eye colour, skin colour, hair colour, earlobe shape, etc. are all phenotypic traits of an individual.
C
Correct answer
Explanation
In the above question one parent is homozygous recessive, pp, while the other is heterozygous, Pp. With the help of Punnett square, you can see that half of the offspring will be homozygous, thus purple, and half will be white.
C
Correct answer
Explanation
As per the question, by constructing the Punnet square for two heterozygous parents, you can observe that 25% will be homozygous dominant, 25% homozygous recessive, and 50% heterozygous. Thus, 75% will be purple.
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incomplete dominance
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co-dominance
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sex-linked dominance
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epistasis
A
Correct answer
Explanation
Snapdragons and four-o-clock plants produce F1heterozygotes in which blending of dominant and recessive traits take place and this is termed as incomplete dominance.The dominant allele does not mask the phenotypic expression of recessive allele completely.
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It is much composite, having both clinal and discontinuous patterns.
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It follows latitude lines suggesting that climate plays a significant role for determining the above trait.
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It is predictable, with each continent having its own unique type among the inherent populations.
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The people of each continent have their own distinct blood type.
A
Correct answer
Explanation
This suggests that natural selection, migrations, genetic drift, the founder principle, and non-random mating were all potentially important factors in our evolutionary history.
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genetically inherited
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acquired after birth as a consequence of certain specific environmental factors
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genetically inherited but get changed after birth as a consequence of natural selection
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genetically inherited but determined by natural selection
A
Correct answer
Explanation
Blood types are acquired only by inheritance from parents and they cannot be changed. However, natural selection can have an effect on whether an individual survives to reproduce and pass on the alleles for his or her blood type.
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The worldwide distribution patterns for the ABO blood system signifies the typological model of human variation.
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Human blood can be unambiguously typed, i.e. there is no degree of difference.
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Mapping the distribution of blood types has proven to be insignificant tool for studying the nature of human variation.
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Human blood cannot be unambiguously typed.
B
Correct answer
Explanation
Unlike such traits as skin colour and hair texture, blood comes in specific, non-blending types. There are no shades of difference--you cannot be halfway between type O and A.
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They very nicely overlap indicating that whatever factors have been selecting for type B have also been at work selecting for type O.
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Where type O is relatively high in frequency, type B is ultimately relatively low.
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They both are very alike to the distribution pattern of skin colour indicating that the same factors have been favoured for blood types and skin pigmentation.
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Where type B is relatively high in frequency, type O is relatively low.
B
Correct answer
Explanation
Type O is most common among Native Americans. However, type B is extremely low in Americans.
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1 out of 4
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2 out of 4
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3 out of 4
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4 out of 4
B
Correct answer
Explanation
There will be a 50% chance (2 out of 4) of having a carrier (Aa) child. Similarly, each time there will be a 25% chance of having an offspring who will inherit the disease (aa) and die.