MCQ Question for Class 12 Biology Chapter 5 Principles of Inheritance and Variation

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Principles of Inheritance and Variation Class 12 Biology MCQs Questions with Answers

Refer below for MCQ Class 12 Biology Chapter 5 Principles of Inheritance and Variation with solutions. Solve questions and compare with the answers provided below

Question. In XO type sex determination male and female have
(a) Equal number of chromosomes
(b) Females have one more chromosome
(c) Males have one more chromosome
(d) Females have two extra chromosomes

Question. When insects having X chromosome in Male sperm fertilizes the egg it produces?
(a) Male with X chromosomes
(b) Female with XX chromosomes
(c) Female with one less chromosome
(d) None of these

Question. Homogametic sex chromosomes are present in females of
(a) Humans and birds
(b) Humans and D. melanogaster
(c) Birds and insects
(d) None of these

Question. Female birds contains
(a) ZZ chromosomes
(b) XX chromosomes
(c) XO chromosomes
(d) None of these

Question. Female heterogamety is present in
(a) Drosophila melanogaster
(b) Homo sapiens
(c) Gallus gallus domesticus(chicken)
(d) None of these

Question. In birds with female heterogamety what determines the male sex of the offspring
(a) Chromosome present in sperm which fertilizes the egg
(b) Chromosome present in egg which fertilizes the sperm
(c) Temperature of body at the time of fertilization
(d) All of these

Question. Which of the following is responsible for alteration in DNA sequences?
(a) Monohybrid cross
(b) Replication
(c) Mutation
(d) None of these

Question. Example of point mutation is
(a) Malaria
(b) Sickle cell anemia
(c) Thyroid
(d) None of these

Question. Which statement is true for pedigree analysis?
(a) This was made for studying the inheritance pattern of traits in human
(b) Control crosses were not possible in humans so inheritance pattern studied
(c) Analysis of inheritance of particular trait in several generations of family is called pedigree analysis
(d) All of these

Question. Which statement is true for X linked recessive trait?
(a) Shows inheritance from carrier female to male progeny
(b) Haemophilia is an example of this type of inheritance
(c) Haemophilia is a disorder in which person’s blood clotting ability is hampered
(d) All are true

Question. Family pedigree of queen Victoria shows inheritance of which disease
(a) Haemophilia
(b) Sickle cell anemia
(c) Phenylketoneuria
(d) Thalesemia

Question. Hb^s peptide for sickle cell anaemia have alteration at which amino acid of the beta globin chain
(a) 4
(b) 7
(c) 6
(d) None of these

Question. The Template strand sequence of DNA of sickle cell anaemia having valine (amino acid code GUG) in
(a) CTC
(b) GAG
(c) GUG
(d) None of these

Question. X linked recessive disorder
(a) Transfers character from male parent to male child
(b) Female carriers to male child
(c) Female carries to female child
(d) Both 2 and 3

Question. Phenylketonuria
(a) Inborn error of metabolism
(b) It is an autosomal recessive genetic disorder
(c) Affected individual converts phenyl alanine to phenylpyruvic acid and other derivatives and causes mental retardation
(d) All of these

Question. During cell division, failure of segregation of chromatids results in
(a) Aneuploidy
(b) Aploidy
(c) Haploidy
(d) None of these

Question. Failure of cytokinesis results in
(a) Aneuploldy
(b) Aploidy
(c) Polyploidy
(d) None of these

Question. Trisomy is
(a) Additional copy of one chromosome is present in a pair
(b) It ‘s a type of chromosomal disorder
(c) It is due to failure of cytokinesis
(d) The chromatids are not able to segregate during cell division and result in trisomy, ex. Down syndrome

Question. Turner’s syndrome is due to
(a) Aneuploidy
(b) Monosomy
(c) 44 + XO
(d) All are true

Question. Among the following characters, which one was not considered by Mendel in his experiments on pea?
(a) Trichomes-Glandular or non-glandular 
(b) Seed-Green or yellow
(c) Pod-Inflated or constricted
(d) Stem-Tall or dwarf

Question. Of a normal couple, half the sons are haemophiliac while half the daughters are carriers. The gene is located on
(a) X-chromosome of father
(b) Y-chromosome of father
(c) one X-chromosome of mother     
(d) both the X-chromosomes of mother. 

Question. The genes controlling the seven pea characters studied by Mendel are now known to be located on how many different chromosomes?
(a) Seven
(b) Six
(c) Five
(d) Four 

Question. Independent assortment of genes does not take place when
(a) genes are located on homologous chromosomes
(b) genes are linked and located on same chromosome     
(c) genes are located on non-homogenous chromosome
(d) all of these.

Question. Which contribute to the success of Mendel?
(a) Qualitative analysis of data
(b) Observation of distinct inherited traits
(c) His knowledge of biology
(d) Consideration of one character at one time 

Question. 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 possible?
(a) 3 genotypes; 4 phenotypes
(b) 4 genotypes; 3 phenotypes   
(c) 4 genotypes; 4 phenotypes
(d) 3 genotypes; 3 phenotypes

Question. A male human is heterozygous for autosomal genes A and B and is also hemizygous for haemophilic gene h. What proportion of his sperms will be abh?
(a) 1/8       
(b) 1/32
(c) 1/16
(d) 1/4

Question. A holandric gene cause hypertrichosis.When a man with hypertrichosis marries a normal women, what percentage of their daughters would be expected to have hypertrichosis?
a) 50%
b) 25%
c) 75%
d) 0%

Question. A phenomenon of a single gene regulating several phenotypes is called
a) Multiple allelism
b) Pleiotropy
c) Incomplete dominance
d) Co-dominance

Question. Round seed is dominant over wrinkled seeds in Pea. If homozygous, round seeded Pea plants are crossed with wrinkled seeded plants, the offsprings will be
a) All round
b) All wrinkled
b) 75% round and 25% wrinkled
d) 50% round and 50% wrinkled

Question. X – linked recessive gene is
a) Always expressed in male
b) Always expressed in female
c) Never expressed in males
d) Always expressed in males and female

Question. Which one is an example for chromosomal mutation
a) Sickle cell anemia
b) Muscular dystrophy
c) Phenylketoneuria
d) Klinefelter’s syndrome

Question. Indicate, the inheritance of which of the following is controlled by multiple alleles
a) Colour blindness
b) Sickle cell anemia
c) Blood group
d) Phenylketoneuria

Question. Segregation of genes occurs in
a) Embryo formation
b) Anaphase II
c) Anaphase I
d) Metaphase II

Question. Child has blood group “O” and his father is “B” type. Then genotype of the father should be
a) IBIB
b) IBIO
c) IAIB
d) IOIO

Question. HbA and HbS alleles of normal and sickle cell haemoglobin are
a) Co-dominant alleles
b) Multiple alleles
c) Dominant-recessive alleles
d) Cumulative alleles

Question. In birds, females are
a) XX
b) ZZ
c) ZO
d) ZW

Question. The plant in which Hugo de Vries introduces the concept of mutation is
a) Oenothera lamarkiana
b) Pisum sativum
c) Allium cepa
d) Mirabilis jalapa

Question. In Snapdragon 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 1 white. What could be the genotype of the two plants used for hybridization? Red flower colour is determined by RR and white by rr genes.
a) Rr
b) rr
c) rrr
d) RR

Question. Skin colour is controlled by
a) Pleiotropic genes
b) Dominant genes
c) Polygenes
d) Recessive gene

Question. Test cross is a cross between
a) Hybrid x Dominant parent
b) Hybrid x Recessive parent
c) Hybrid x Hybrid
d) Dominant parent x Recessive parent

Question. Which of the following condition is called monosomics
a) 2n+1
b) 2n+2
c) 2n-1
d) n+1

Question. Experimental verification of the chromosomal theory of inheritance was done by
(a) Mendel
(b) Sutton
(c) Boveri
(d) Morgan.     

Question. Multiple alleles are present
(a) at the same locus of the chromosome   
(b) on non-sister chromatids
(c) on different chromosomes
(d) at different loci on the same chromosome

Question. 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 were in the ratio of
(a) 3 : 1 : : Tall : Dwarf
(b) 3 : 1 : : Dwarf : Tall
(c) 1 : 2 : 1 : : Tall homozygous : Tall heterozygous : Dwarf   
(d) 1 : 2 : 1 : : Tall

Question. F2 generation in a Mendelian cross showed that both genotypic and phenotypic ratios are same as 1 : 2 : 1. It represents a case of
(a) co-dominance
(b) dihybrid cross
(c) monohybrid cross with complete dominance
(d) monohybrid cross with incomplete dominance.   

Question. The genotype of a plant showing the dominant phenotype can be determined by
(a) test cross     
(b) dihybrid cross
(c) pedigree analysis
(d) back cross.

Question. Mendel’s last law is
(a) segregation
(b) dominance
(c) independent assortment       
(d) polygenic inheritance.

Question. 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 1 white. What could be the genotype of the two plants used for hybridisation? Red flower colour is determined by RR and white by rr genes.
(a) rrrr
(b) RR
(c) Rr       
(d) rr

Question. In a genetic cross having recessive epistasis, F2 phenotypic ratio would be
(a) 9 : 6 : 1
(b) 15 : 1
(c) 9 : 3 : 4       
(d) 12 : 3 : 1.

Question. An abnormal human male phenotype involving an extra X-chromosome (XXY) is a case of
(a) Edward’s syndrome
(b) Klinefelter’s syndrome         
(c) intersex
(d) Down’s syndrome.

Question. Test cross involves
(a) crossing between two genotypes with dominant trait
(b) crossing between two genotypes with recessive trait
(c) crossing between two F1 hybrids
(d) crossing the F1 hybrid with a double recessive genotype     

Question. In hybridisation, Tt × tt gives rise to the progeny of ratio
(a) 2 : 1
(b) 1 : 2 : 1
(c) 1 : 1             
(d) 1 : 2. (1999)   

 Question. A child’s blood group is ‘O’. The parent’s blood groups cannot be
(a) A and B
(b) A and A 
(c) AB and O   
(d) B and O.

Question. An organism with two identical alleles is
(a) dominant
(b) hybrid
(c) heterozygous
(d) homozygous.     

Question. In human beings 45 chromosomes/single X/XO abnormality causes
(a) Down’s syndrome
(b) Kinefelter’s syndrome
(c) Turner’s syndrome       
(d) Edward’s syndrome.

Question. tt mates with Tt. What will be characteristic of offspring?
(a) 75% recessive
(b) 50% recessive         
(c) 25% recessive
(d) All dominant

Question. A human male produces sperms with the genotypes AB, Ab, aB and ab pertaining to two diallelic characters in equal proportions. What is the corresponding genotype of this person?
(a) AaBB
(b) AABb
(c) AABB
(d) AaBb       

Question. In a test cross involving F1 dihybrid flies, more parental-type offspring were produced than the recombinant-type offspring. This indicates
(a) the two genes are linked and present on the same chromosome 
(b) both of the characters are controlled by more than one gene
(c) the two genes are located on two different chromosomes
(d) chromosomes failed to separate during meiosis.

Question. When two unrelated individuals or lines are crossed, the performance of F1 hybrid is often superior to both its parents. This phenomenon is called
(a) heterosis         
(b) transformation
(c) splicing
(d) metamorphosis.

Question. Male XX and female XY sometime occur due to
(a) deletion
(b) transfer of segments in X and Y chromosome   
(c) aneuploidy
(d) hormonal imbalance.

Question. Which of the following is suitable for experiment on linkage?
(a) aaBB × aaBB
(b) AABB × aabb   
(c) AaBb × AaBb
(d) AAbb × AaBB

Question. A normal green male maize is crossed with albino female. The progeny is albino because
(a) trait for a albinism is dominant
(b) the albinos have biochemical to destroy plastids derived from green male
(c) plastids are inherited from female parent       
(d) green plastids of male must have mutated.

Question. In order to find out the different types of gametes produced by a pea plant having the genotype AaBb it should be crossed to a plant with the genotype
(a) AABB
(b) AaBb
(c) aabb       
(d) aaBB.

Question. Two non-allelic genes produces the new phenotype when present together but fail to do so independently then it is called
(a) epistasis     
(b) polygene
(c) non complementary gene
(d) complementary gene.

Question. A fruit fly is heterozygous for sex-linked genes, when mated with normal female fruit fly, the males specific chromosome will enter egg cell in the proportion
(a) 3 : 1
(b) 7 : 1
(c) 1 : 1     
(d) 2 : 1.

Question. Down’s syndrome in humans is due to
(a) three ‘X’ chromosomes
(b) three copies of chromosome 21     
(c) monosomy
(d) two ‘Y’ chromosomes

Question. Which one is a hereditary disease?
(a) Cataract
(b) Leprosy
(c) Blindness
(d) Phenylketonuria     

Question. Segregation of Mendelian factors (no linkage, no crossing over) occurs during
(a) anaphase I       
(b) anaphase II
(c) diplotene
(d) metaphase I.

Question. When a single gene influences more than one trait it is called
(a) pseudodominance
(b) pleiotropy     
(c) epistasis
(d) none of these.

Question. Thalassemia and sickle cell anaemia are caused due to a problem in globin molecule synthesis. Select the correct statement.
(a) Both are due to a quantitative defect in globin chain synthesis.
(b) Thalassemia is due to less synthesis of globin molecules.     
(c) Sickle cell anaemia is due to a quantitative problem of globin molecules.
(d) Both are due to a qualitative defect in globin chain synthesis.

Question. 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 being colour blind ?
(a) Nil
(b) 0.25     
(c) 0.5
(d) 1

Question. Select the incorrect statement from the following.
(a) Galactosemia is an inborn error of metabolism.
(b) Small population size results in random genetic drift in a population.
(c) Baldness is a sex-limited trait. 
(d) Linkage is an exception to the principle of independent assortment in heredity.

Question. A man and a woman, who do not show any apparent signs of a certain inherited disease, have seven children (2 daughters and 5 sons). Three of the sons suffer from the given disease but none of the daughters affected. Which of the following mode of inheritance do you suggest for this disease?
(a) Sex-linked dominant
(b) Sex-linked recessive       
(c) Sex-limited recessive
(d) Autosomal dominant

Question. A diseased man marries a normal woman. They get three daughters and five sons. All the daughters were diseased and sons were normal. The gene of this disease is
(a) sex linked dominant       
(b) sex linked recessive
(c) sex limited character
(d) autosomal dominant.

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