Principles of Inheritance and Variation
Previous Years Questions

MCQ (Single Correct Answer)

A man whose father was colour blind marries a women who had a colour blind mother and normal father. What percentage of male children of this couple w...
Fruit colour in squash is an example of :
A human female with Turner’s syndrome :
A gene showing codominance has :
A colour blind man marries a woman with normal sight who has no history of colour blindness in her family. What is the probability of their grandson b...
A pleiotropic gene -
In his classic experiments on pea plants, Mendel did not use :
The term "linkage" was coined by -
In the following human pedigree, the filled symbols represent the affected individuals. Identify the type of given pedigree. ...
Given below are two statements: Statement I : Sickle cell anaemia and haemophilia are autosomal dominant traits. Statement II : Sickle cell anaemia an...
In meiosis, crossing over and exchange of genetic material between homologous chromosomes are catalyzed by the enzyme
The chromosomal theory of inheritance was proposed by
What is the expected percentage of F2 progeny with yellow and inflated pod in dihybrid cross experiment involving pea plants with green coloured, infl...
A normal girl, whose mother is haemophilic marries a male with no ancestral history of haemophilia. What will be the possible phenotypes of the offspr...
XO type of sex determination can be found in :
Given below are two statements: Statement I : Mendel studied seven pairs of contrasting traits in pea plants and proposed the Laws of Inheritance. Sta...
Which of the following occurs due to the presence of autosome linked dominant trait?
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Mendel's law of independent...
The production of gametes by the parents, formation of zygotes, the F1 and F2 plants, can be understood from a diagram called :
Now-a-days it is possible to detect the mutated gene causing cancer by allowing radioactive probe to hybridise its complimentary DNA in a clone of cel...
In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased?
Experimental verification of the chromosomal theory of inheritance was done by
Embryological support for evolution was disapproved by
Select the correct match
How many true breeding pea plant varieties did Mendel select as pairs, which were similar except in one character with contrasting traits?
In Antirrhinum (Snapdragon), a red flower was crossed with a white flower and in F1 generation, pink flowers were obtained. When pink flowers were sel...
The frequency of recombination between gene pairs on the same chromosome as a measure of the distance between genes was explained by :
What is the genetic disorder in which an individual has an overall masculine development, gynaecomastia, and is sterile?
What map unit (Centimorgan) is adopted in the construction of genetic maps?
A gene locus has two alleles A, a. If the frequency of dominant allele A is 0.4, then what will be the frequency of homozygous dominant, heterozygous ...
Select the incorrect statement.
Which of the following characteristics represent 'Inheritance of blood groups' in humans? a. Dominance b. Co-dominance c. Multiple allele d. Incom...
Which of the following pairs is wrongly matched?
A woman has an X-linked condition on one of her X chromosomes. This chromosome can be inherited by
Thalassemia and sickle cell anemia are caused due to a problem in globin molecule synthesis. Select the correct statement.
The genotypes of a Husband and Wife are IAIB and IAi. Among the blood types of their children, how many different genotypes and phenotypes are possibl...
A disease caused by an autosomal primary non-disjunction is :
Which one from those given below is the period for Mendel’s hybridisation experiments ?
Among the following characters, which one was not considered by Mendel in his experiments on pea?
The mechanism that causes a gene to move from one linkage group to another is called
If a colour-blind man marries a woman who is homozygous for normal colour vision, the probability of their son being colour-blind is
In a testcross involving F1 dihybrid flies, more parental-type offspring were produced than the recombinant-typeoffspring. This indicates
Which of the following most appropriately describes haemophilia ?
Match the terms in Column-I with their description in Column-II and choose the correct option : .tg {border-collapse:collapse;border-spacing:0;width...
A cell at telophase stage is observed by a student in a plant brought from the field. He tells his teacher that this cell is not like other cells at t...
Pick out the correct statements : (a) Haemophilia is a sex-linked recessive disease. (b) Down's syndrome is due to aneuploidy. (c) Phenylketonuria is ...
A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the F1 plants were selfed the resulting genotypes w...
The movement of a gene from one linkage group to another is called
Alleles are
A man with blood group ‘A’ marries a woman with blood group ‘B’. What are all the possible blood groups of their offsprings?
How many pairs of contrasting characters in pea plants were studied by Mendel in his experiments?
Multiple alleles are present
An abnormal human baby with ‘XXX’ sex chromosomes was born due to
Down's syndrome in humans is due to :
Which one is the incorrect statement with regards to the importance of pedigree analysis?
Select the incorrect statement with regard to Haemophilia is :
Which idea is depicted by a cross in which the F1 generation resembles both the parents?
If two persons with 'AB' blood group marry and have sufficiently large number of children, these children could be classified as 'A' blood group : 'AB...
Which of the following cannot be detected in a developing foetus by amniocentesis ?
If both parents are carriers for thalessemia, which is an autosomal recessive disorder, what are the chances of pregnancy resulting in an affected chi...
Represented below is the inheritance pattern of the certain type of traits in humans. Which one of the following conditions could be an example of thi...
A test cross is carried out to :
Which one of the following is a wrong statement regarding mutations ?
A normal - visioned man whose father was colour bilind, marries a woman whose father was also colour - blind. They have their first child as a daughte...
F2 generation in a Mendelian cross showed that both genotypic and phenotypic ratios are same as 1 : 2 : 1. It represents a case of
Which one of the following conditions of the zygotic cell would lead to the birth of a normal human female child ?
Test cross in plants or in Drosophila involves crossing :
When two unrelated individuals or lines are crossed, the per romance of F1 hybrid is often superior to both parents. This phenomenon is called :
Which one of the following conditions correctly describes the manner of determining the sex ?
Mutations can be induced with :
ABO blood grouping is controlled by gene I which has three alleles and show co-dominance. There are six genotypes. How many phenotypes in all are poss...
Study the pedigree chart of a certain family given below and select the correct conculusion which can be drawn for the character – ...
A cross in which an organism showing a dominant phenotype in crossed with the recessive parent in order to know its genotype is called -
In antirrhinum two plants with pink flowers were hybridized. The F1 plants produced red, pink and white flowers in the proportion of 1 red, 2 pink and...
Which one of the following symbols and its representation, used in human pedigree analysis is correct –
ABO blood groups in humans are controlled by the gene I. It has three alleles – IA, IB and i. Since there are three different alleles, six different ...
Select the correct statement from the ones given below with respect to dihybrid cross –
The genotype of a plant showing the dominant phenotype can be determined by –
Which one of the following cannot be explained on the basis of Mendel's Law of Dominance?
Select the incorrect statement from the following :
Sickle-cell anemia is :
The genetic defect-adenosine deaminase (ADA) deficiency may be cured permanently by
The most popularly known blood grouping is the ABO grouping. It is named ABO and not ABC, because "O" in it refers to having :
Study the pedigree chart given below : What does it show ? ...
Which one of the following conditions in humans is correctly matched with its chromosomal abnormality/linkage?
A human male produces sperms with the genotypes AB, Ab, AB, and ab pertaining to two diallelic characters in equal proportions. What is the correspond...
In pea plants, yellow seeds are dominant to green. If a heterozygous yellow seeded plant is crossed with a green seeded plant, what ratio of yellow an...
Inheritance of skin colour in humans is an example of:-
A common test to find the genotype of a hybrid is by:-
In the hexaploid wheat, the haploid(n) and basic(x) numbers of chromosomes are:
Test cross involves-
Both sickle cell anemia and Huntington's chorea are-
If a colour blind woman marries a normal visioned man, their sons will be
Cri-du-chat syndrome in humans is caused by the-
In Mendel's experiments with garden pea, round seed shape (RR) was dominant over wrinkled seeds (rr), yellow cotyledon (YY) was dominant over green co...
Sickle cell anaemia has not been eliminated from the African population because-
How many different kinds of gametes will be produced by a plant having the genotype AABbCC ?
Which one of the following is an example of polygenic inheritance ?
Phenotype of an organism is the result of-
In order to find out the different types of gametes produced by a pea plants having the genotype AaBb, it should be crossed to a plant with the genoty...
G-6-P dehydrogenase deficiency is associated with haemolysis of -
A man and a woman, who do not show any apparent signs of a certain inherited disease, have seven children (2 daughter and 5 sons). Three of the sons s...
A women with 47 chromosomes due to three copies of chromosome 21 is characterized by -
Haemophilia is more commonly seen in human males than in human females because -
A woman with normal vision, but whose father was colour bind, marries a colour blind man. Suppose that the fourth child of this couple was a boy. This...
Which of the following is not a hereditary disease ?
A women with 47 chromosomes due to three copies of chromosome 21 is characterized by
In a plant, red fruit (R) is dominant over yellow fruit (r) and tallness (T) is dominant over shortness (t). If a plant with RRTt genotype is crossed ...
A male human is heterozygous for autosomal genes A and B and is also hemizygous for hemophilic gene h. What proportion of his sperms will be abh :-
Lack of independent assortment of two genes A and B in fruit fly Drosophila is due to :-
One of the parents of a cross has a mutation in its mitochondria. In that cross, that parent is taken as a male. During segregation of F2 progenies th...
A normal woman, whose father was colour-blind is married to a normal man. The sons would be :-
The recessive genes located on X-chromosomes in humans are always-
Which one of the following traits of garden pea studied by Mendel was a recessive feature ?
The genes controlling the seven pea characters studied by Mendel are now known to be located on how many different chromosomes ?
Two crosses between the same pair of genotypes or phenotypes in which the sources of the gametes are reversed in one cross, is known as : -
Pattern baldness, moustaches and beard in human males are examples of : -
In Drosophila, the sex is determined by : -
Down's syndrome is caused by an extra copy of chromosome number 21. What percentage of offspring produced by an affected mother and a normal father wo...
Which one of the following conditions though harmful in itself, is also a potential saviour from a mosquito borne infectious disease ?
Which of the following is the example of pleiotropy ?
There are three genes a, b and c. The percentage of crossing over between a and b is 20%, b and c is 28% and a and c is 8%. What is the sequence of ge...
On selfing a plant of F1 generation with genotype “AABbCC”,the genotypic ratio in F2 generation will be
A gene said to be dominant if : -
A diseased man marries a normal woman. They get three daughter and five sons. All the daughter were diseased and sons were normal. The gene of this di...
Which of the following is a correct match -
Two nonallelic genes produces the new phenotype when present together but fail to do so independently then it is called : -
Ratio of complementry genes is : -
When dominant and recessive allels express itself together it is called : -
A and B genes are linked. What shall be genotype of progeny in a cross between AB/ab and ab/ab : -
Independent assortment of genes does not takes place when : -
Number of Barr bodies in XXXX female is
Sickle cell anaemia is induce to : -
Male XX and female XY sometime occur due to
Probability of four son to a couple is : -
According to mendelism which character is showing dominance ?
Due to the cross between TTRr × ttrr the resultant progenies showed how many percent plants tall, red flowered :
Mongolian idiots are due to trisomy in 21st chromosome is called :
Erythroblastosis foetalis is caused when :
In Drosophila the XXY condition leads to femaleness whereas in human beings the same condition leads to Klienfelter's syndrome in male. It proves :
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